-
Question 1
Incorrect
-
A child presents with blurred vision, nausea, vomiting, and low sodium levels. They are taking carbamazepine for epilepsy. You suspect toxicity and send bloods for assessment.
What is the recommended therapeutic range for carbamazepine in children?Your Answer: 15-20 mg/L
Correct Answer: 4-10 mg/L
Explanation:The therapeutic range for carbamazepine is between 4 and 10 mg/L. This range indicates the optimal concentration of the medication in the bloodstream for it to be effective in treating certain conditions. It is important for healthcare professionals to monitor the levels of carbamazepine in a patient’s blood to ensure they are within this range. If the levels are too low, the medication may not be effective, while levels that are too high can lead to potential side effects. By maintaining carbamazepine levels within the therapeutic range, healthcare providers can maximize the benefits of the medication while minimizing any potential risks.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 2
Correct
-
A 35 year old male presents to the emergency department and admits to ingesting 60 paracetamol tablets 9 hours ago. What is the primary intervention for this patient?
Your Answer: N-acetylcysteine
Explanation:N-acetylcysteine (NAC) enhances the production of glutathione, a substance that helps in the detoxification process. Specifically, NAC aids in the conjugation of NAPQI, a harmful metabolite of paracetamol, with glutathione, thereby neutralizing its toxicity.
Further Reading:
Paracetamol poisoning occurs when the liver is unable to metabolize paracetamol properly, leading to the production of a toxic metabolite called N-acetyl-p-benzoquinone imine (NAPQI). Normally, NAPQI is conjugated by glutathione into a non-toxic form. However, during an overdose, the liver’s conjugation systems become overwhelmed, resulting in increased production of NAPQI and depletion of glutathione stores. This leads to the formation of covalent bonds between NAPQI and cell proteins, causing cell death in the liver and kidneys.
Symptoms of paracetamol poisoning may not appear for the first 24 hours or may include abdominal symptoms such as nausea and vomiting. After 24 hours, hepatic necrosis may develop, leading to elevated liver enzymes, right upper quadrant pain, and jaundice. Other complications can include encephalopathy, oliguria, hypoglycemia, renal failure, and lactic acidosis.
The management of paracetamol overdose depends on the timing and amount of ingestion. Activated charcoal may be given if the patient presents within 1 hour of ingesting a significant amount of paracetamol. N-acetylcysteine (NAC) is used to increase hepatic glutathione production and is given to patients who meet specific criteria. Blood tests are taken to assess paracetamol levels, liver function, and other parameters. Referral to a medical or liver unit may be necessary, and psychiatric follow-up should be considered for deliberate overdoses.
In cases of staggered ingestion, all patients should be treated with NAC without delay. Blood tests are also taken, and if certain criteria are met, NAC can be discontinued. Adverse reactions to NAC are common and may include anaphylactoid reactions, rash, hypotension, and nausea. Treatment for adverse reactions involves medications such as chlorpheniramine and salbutamol, and the infusion may be stopped if necessary.
The prognosis for paracetamol poisoning can be poor, especially in cases of severe liver injury. Fulminant liver failure may occur, and liver transplant may be necessary. Poor prognostic indicators include low arterial pH, prolonged prothrombin time, high plasma creatinine, and hepatic encephalopathy.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 3
Correct
-
A patient with a known history of asthma presents with symptoms of theophylline toxicity after starting a new medication.
Which of the following drugs is most likely causing this interaction?Your Answer: Fluconazole
Explanation:Theophylline, a medication commonly used to treat respiratory conditions, can be affected by certain drugs, either increasing or decreasing its plasma concentration and half-life. Drugs that can increase the plasma concentration of theophylline include calcium channel blockers like verapamil, cimetidine, fluconazole, macrolides such as erythromycin, methotrexate, and quinolones like ciprofloxacin. On the other hand, drugs like carbamazepine, phenobarbitol, phenytoin (and fosphenytoin), rifampicin, and St. John’s wort can decrease the plasma concentration of theophylline. It is important to be aware of these interactions when prescribing or taking theophylline to ensure its effectiveness and avoid potential side effects.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 4
Incorrect
-
You observe that a patient's temperature has risen to 41.5ºC after undergoing rapid sequence induction. You are worried that the patient might have developed malignant hyperthermia. What is the primary drug used to treat malignant hyperthermia?
Your Answer: Diazepam
Correct Answer: Dantrolene
Explanation:The primary treatment for malignant hyperthermia is dantrolene. Dantrolene works by blocking the release of calcium through calcium channels, resulting in the relaxation of skeletal muscles.
Further Reading:
Malignant hyperthermia is a rare and life-threatening syndrome that can be triggered by certain medications in individuals who are genetically susceptible. The most common triggers are suxamethonium and inhalational anaesthetic agents. The syndrome is caused by the release of stored calcium ions from skeletal muscle cells, leading to uncontrolled muscle contraction and excessive heat production. This results in symptoms such as high fever, sweating, flushed skin, rapid heartbeat, and muscle rigidity. It can also lead to complications such as acute kidney injury, rhabdomyolysis, and metabolic acidosis. Treatment involves discontinuing the trigger medication, administering dantrolene to inhibit calcium release and promote muscle relaxation, and managing any associated complications such as hyperkalemia and acidosis. Referral to a malignant hyperthermia center for further investigation is also recommended.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 5
Incorrect
-
A 60-year-old woman has developed a thick cord of tissue on the sole of her left foot. She has developed a flexion deformity with her toes curled downwards. She is unable to straighten them. She has a history of epilepsy, which is well managed with her current anticonvulsant medication. A picture of her foot deformity is displayed below:
What is the MOST LIKELY anticonvulsant that is responsible for this deformity?Your Answer: Sodium valproate
Correct Answer: Phenytoin
Explanation:This individual has developed Dupuytren’s contracture, which is a hand deformity characterized by a fixed flexion caused by palmar fibromatosis. The only anticonvulsant treatment believed to be connected to the development of Dupuytren’s contracture is phenytoin. Additionally, other conditions associated with its occurrence include liver cirrhosis, diabetes mellitus, alcoholism, and trauma.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 6
Incorrect
-
A 42-year-old woman with a long history of anxiety presents having taken a deliberate overdose of the medication she takes for a thyroid condition. She informs you that the medication she takes for this condition is levothyroxine 100 mcg. She consumed the medication approximately 30 minutes ago but was promptly discovered by her husband, who quickly brought her to the Emergency Department.
Which of the following tests will be most beneficial initially?Your Answer: Urinalysis
Correct Answer: Arterial blood gas
Explanation:Calcium-channel blocker overdose is a serious condition that should always be taken seriously as it can be potentially life-threatening. The two most dangerous types of calcium channel blockers in overdose are verapamil and diltiazem. These medications work by binding to the alpha-1 subunit of L-type calcium channels, which prevents the entry of calcium into the cells. These channels play a crucial role in the functioning of cardiac myocytes, vascular smooth muscle cells, and islet beta-cells.
Significant toxicity can occur with the ingestion of more than 10 tablets of verapamil (160 mg or 240 mg immediate or sustained-release capsules) or diltiazem (180 mg, 240 mg or 360 mg immediate or sustained-release capsules). In children, even 1-2 tablets of immediate or sustained-release verapamil or diltiazem can be harmful. Symptoms usually appear within 1-2 hours of taking standard preparations, but with slow-release versions, the onset of severe toxicity may be delayed by 12-16 hours, with peak effects occurring after 24 hours.
The main clinical manifestations of calcium-channel blocker overdose include nausea and vomiting, low blood pressure, slow heart rate and first-degree heart block, heart muscle ischemia and stroke, kidney failure, pulmonary edema, and high blood sugar levels.
When managing a patient with calcium-channel blocker overdose, certain bedside investigations are crucial. These include checking blood glucose levels, performing an electrocardiogram (ECG), and obtaining an arterial blood gas sample. Additional investigations that can provide helpful information include assessing urea and electrolyte levels, conducting a chest X-ray to check for pulmonary edema, and performing an echocardiography.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 7
Incorrect
-
A 70-year-old patient comes in after a chronic overdose of digoxin. She has experienced multiple episodes of vomiting, feels extremely tired, and reports that her vision seems to have a yellow tint.
What is the indication for administering DigiFab in this patient?Your Answer:
Correct Answer: Coexistent renal failure
Explanation:Digoxin-specific antibody (DigiFab) is an antidote used to counteract digoxin overdose. It is a purified and sterile preparation of digoxin-immune ovine Fab immunoglobulin fragments. These fragments are derived from healthy sheep that have been immunized with a digoxin derivative called digoxin-dicarboxymethoxylamine (DDMA). DDMA is a digoxin analogue that contains the essential cyclopentanoperhydrophenanthrene: lactone ring moiety coupled to keyhole limpet hemocyanin (KLH).
DigiFab has a higher affinity for digoxin compared to the affinity of digoxin for its sodium pump receptor, which is believed to be the receptor responsible for its therapeutic and toxic effects. When administered to a patient who has overdosed on digoxin, DigiFab binds to digoxin molecules, reducing the levels of free digoxin in the body. This shift in equilibrium away from binding to the receptors helps to reduce the cardiotoxic effects of digoxin. The Fab-digoxin complexes are then eliminated from the body through the kidney and reticuloendothelial system.
The indications for using DigiFab in cases of acute and chronic digoxin toxicity are summarized below:
Acute digoxin toxicity:
– Cardiac arrest
– Life-threatening arrhythmia
– Potassium level >5 mmol/l
– Ingestion of >10 mg of digoxin (in adults)
– Ingestion of >4 mg of digoxin (in children)
– Digoxin level >12 ng/mlChronic digoxin toxicity:
– Cardiac arrest
– Life-threatening arrhythmia
– Significant gastrointestinal symptoms
– Symptoms of digoxin toxicity in the presence of renal failure -
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 8
Incorrect
-
A 21 year old male is brought to the emergency department by his parents and admits to ingesting 48 paracetamol tablets. What are the criteria for administering activated charcoal in this case?
Your Answer:
Correct Answer: Patient presents within 1 hour of ingesting paracetamol and stated dose is in excess of 150 mg/kg
Explanation:Activated charcoal should be given to patients who have ingested paracetamol and meet two criteria: they must present within one hour of ingestion, and they must have taken a dose of paracetamol that is equal to or greater than 150 mg/kg. The recommended dose of activated charcoal is 50g, which is typically administered as 300ml. It is important to note that the dose criteria of 150 mg/kg is based on the amount of paracetamol reported by the patient, not on paracetamol levels, which should not be assessed until at least four hours after ingestion.
Further Reading:
Paracetamol poisoning occurs when the liver is unable to metabolize paracetamol properly, leading to the production of a toxic metabolite called N-acetyl-p-benzoquinone imine (NAPQI). Normally, NAPQI is conjugated by glutathione into a non-toxic form. However, during an overdose, the liver’s conjugation systems become overwhelmed, resulting in increased production of NAPQI and depletion of glutathione stores. This leads to the formation of covalent bonds between NAPQI and cell proteins, causing cell death in the liver and kidneys.
Symptoms of paracetamol poisoning may not appear for the first 24 hours or may include abdominal symptoms such as nausea and vomiting. After 24 hours, hepatic necrosis may develop, leading to elevated liver enzymes, right upper quadrant pain, and jaundice. Other complications can include encephalopathy, oliguria, hypoglycemia, renal failure, and lactic acidosis.
The management of paracetamol overdose depends on the timing and amount of ingestion. Activated charcoal may be given if the patient presents within 1 hour of ingesting a significant amount of paracetamol. N-acetylcysteine (NAC) is used to increase hepatic glutathione production and is given to patients who meet specific criteria. Blood tests are taken to assess paracetamol levels, liver function, and other parameters. Referral to a medical or liver unit may be necessary, and psychiatric follow-up should be considered for deliberate overdoses.
In cases of staggered ingestion, all patients should be treated with NAC without delay. Blood tests are also taken, and if certain criteria are met, NAC can be discontinued. Adverse reactions to NAC are common and may include anaphylactoid reactions, rash, hypotension, and nausea. Treatment for adverse reactions involves medications such as chlorpheniramine and salbutamol, and the infusion may be stopped if necessary.
The prognosis for paracetamol poisoning can be poor, especially in cases of severe liver injury. Fulminant liver failure may occur, and liver transplant may be necessary. Poor prognostic indicators include low arterial pH, prolonged prothrombin time, high plasma creatinine, and hepatic encephalopathy.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 9
Incorrect
-
You refer a patient with a history of recurrent supraventricular arrhythmias to the cardiology on-call team. While discussing the patient with the cardiology registrar on the phone, she explains that she is currently busy, but suggests that you start verapamil now and that she will review the patient as soon as she can. You review the patient's medication chart to determine if this is an appropriate course of action.
Which of the following drugs should not be co-prescribed with verapamil?Your Answer:
Correct Answer: Bisoprolol
Explanation:Verapamil is a type of calcium-channel blocker that is commonly used to treat irregular heart rhythms and chest pain. It is important to note that verapamil should not be taken at the same time as beta-blockers like atenolol and bisoprolol. This is because when these medications are combined, they can have a negative impact on the heart’s ability to contract and the heart rate, leading to a significant drop in blood pressure, slow heart rate, impaired conduction between the upper and lower chambers of the heart, heart failure (due to decreased ability of the heart to pump effectively), and even a pause in the heart’s normal rhythm. For more information, you can refer to the section on verapamil interactions in the British National Formulary (BNF).
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 10
Incorrect
-
You assess a 20-year-old woman who has ingested a combination of drugs 30 minutes prior to her arrival at the emergency department. You contemplate the use of activated charcoal to minimize the absorption of the ingested substances. Which of the following is not susceptible to the effects of activated charcoal?
Your Answer:
Correct Answer: Lithium
Explanation:Activated charcoal is a useful treatment for many drug poisonings, but it is not effective against certain types of poisonings. To remember these exceptions, you can use the mnemonic PHAILS. This stands for Pesticides (specifically organophosphates), Hydrocarbons, Acids (strong), alkalis (strong), alcohols (such as ethanol, methanol, and ethylene glycol), Iron, Lithium, and Solvents.
Further Reading:
Poisoning in the emergency department is often caused by accidental or intentional overdose of prescribed drugs. Supportive treatment is the primary approach for managing most poisonings. This includes ensuring a clear airway, proper ventilation, maintaining normal fluid levels, temperature, and blood sugar levels, correcting any abnormal blood chemistry, controlling seizures, and assessing and treating any injuries.
In addition to supportive treatment, clinicians may need to consider strategies for decontamination, elimination, and administration of antidotes. Decontamination involves removing poisons from the skin or gastrointestinal tract. This can be done through rinsing the skin or using methods such as activated charcoal, gastric lavage, induced emesis, or whole bowel irrigation. However, induced emesis is no longer commonly used, while gastric lavage and whole bowel irrigation are rarely used.
Elimination methods include urinary alkalinization, hemodialysis, and hemoperfusion. These techniques help remove toxins from the body.
Activated charcoal is a commonly used method for decontamination. It works by binding toxins in the gastrointestinal tract, preventing their absorption. It is most effective if given within one hour of ingestion. However, it is contraindicated in patients with an insecure airway due to the risk of aspiration. Activated charcoal can be used for many drugs, but it is ineffective for certain poisonings, including pesticides (organophosphates), hydrocarbons, strong acids and alkalis, alcohols (ethanol, methanol, ethylene glycol), iron, lithium, and solvents.
Antidotes are specific treatments for poisoning caused by certain drugs or toxins. For example, cyanide poisoning can be treated with dicobalt edetate, hydroxocobalamin, or sodium nitrite and sodium thiosulphate. Benzodiazepine poisoning can be treated with flumazanil, while opiate poisoning can be treated with naloxone. Other examples include protamine for heparin poisoning, vitamin K or fresh frozen plasma for warfarin poisoning, fomepizole or ethanol for methanol poisoning, and methylene blue for methemoglobinemia caused by benzocaine or nitrates.
There are many other antidotes available for different types of poisoning, and resources such as TOXBASE and the National Poisons Information Service (NPIS) can provide valuable advice on managing poisonings.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 11
Incorrect
-
A 35-year-old woman has recently started taking a new medication. She is experiencing severe muscle pains.
Which ONE of the following drugs is most likely to cause myopathy as a side effect?Your Answer:
Correct Answer: Simvastatin
Explanation:Statins, although generally safe and well-tolerated, can cause myopathy and myotoxicity. This range of muscle-related side effects can vary from mild muscle pain to the most severe case of rhabdomyolysis, which can lead to kidney failure, blood clotting issues, and even death.
The different levels of myotoxicity associated with statins are as follows:
– Myalgia: muscle symptoms without an increase in creatine kinase (CK) levels.
– Asymptomatic myopathy: elevated CK levels without muscle symptoms.
– Myositis: muscle symptoms with CK levels elevated less than 10 times the upper limit of normal.
– Rhabdomyolysis: muscle symptoms with CK levels elevated more than 10 times the upper limit of normal, potentially leading to myoglobinuria (presence of myoglobin in urine) and renal failure.Most statins are broken down by the cytochrome P450 enzyme system. When taken with drugs that strongly inhibit this system, the concentration of statins in the blood can significantly increase. This, in turn, raises the risk of myopathy. A well-known example of this is the combination of statins with macrolide antibiotics like erythromycin and clarithromycin. Co-prescribing these drugs with statins has been linked to a higher risk of myopathy, hospitalization due to rhabdomyolysis, acute kidney injury, and increased mortality rates.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 12
Incorrect
-
A 32-year-old woman comes to the clinic complaining of palpitations. During an ECG, it is found that she has newly developed QT prolongation. She mentions that her doctor recently prescribed her a new medication and wonders if that could be the reason.
Which of the following medications is most likely to cause QT interval prolongation?Your Answer:
Correct Answer: Citalopram
Explanation:Prolongation of the QT interval can lead to a dangerous ventricular arrhythmia called torsades de pointes, which can result in sudden cardiac death. There are several commonly used medications that are known to cause QT prolongation.
Low levels of potassium (hypokalaemia) and magnesium (hypomagnesaemia) can increase the risk of QT prolongation. For example, diuretics can interact with QT-prolonging drugs by causing hypokalaemia.
The QT interval varies with heart rate, and formulas are used to correct the QT interval for heart rate. Once corrected, it is referred to as the QTc interval. The QTc interval is typically reported on the ECG printout. A normal QTc interval is less than 440 ms.
If the QTc interval is greater than 440 ms but less than 500 ms, it is considered borderline. Although there may be some variation in the literature, a QTc interval within these values is generally considered borderline prolonged. In such cases, it is important to consider reducing the dose of QT-prolonging drugs or switching to an alternative medication that does not prolong the QT interval.
A prolonged QTc interval exceeding 500 ms is clinically significant and is likely to increase the risk of arrhythmia. Any medications that prolong the QT interval should be reviewed immediately.
Here are some commonly encountered drugs that are known to prolong the QT interval:
Antimicrobials:
– Erythromycin
– Clarithromycin
– Moxifloxacin
– Fluconazole
– KetoconazoleAntiarrhythmics:
– Dronedarone
– Sotalol
– Quinidine
– Amiodarone
– FlecainideAntipsychotics:
– Risperidone
– Fluphenazine
– Haloperidol
– Pimozide
– Chlorpromazine
– Quetiapine
– ClozapineAntidepressants:
– Citalopram/escitalopram
– Amitriptyline
– Clomipramine
– Dosulepin
– Doxepin
– Imipramine
– LofepramineAntiemetics:
– Domperidone
– Droperidol
– Ondansetron/GranisetronOthers:
– Methadone
– Protein kinase inhibitors (e.g. sunitinib) -
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 13
Incorrect
-
A 60-year-old patient with type II diabetes mellitus has ingested an excessive amount of gliclazide.
What are the possible antidotes that can be administered in cases of sulphonylurea poisoning?Your Answer:
Correct Answer: Octreotide
Explanation:There are various specific remedies available for different types of poisons and overdoses. The following list provides an outline of some of these antidotes:
Poison: Benzodiazepines
Antidote: FlumazenilPoison: Beta-blockers
Antidotes: Atropine, Glucagon, InsulinPoison: Carbon monoxide
Antidote: OxygenPoison: Cyanide
Antidotes: Hydroxocobalamin, Sodium nitrite, Sodium thiosulphatePoison: Ethylene glycol
Antidotes: Ethanol, FomepizolePoison: Heparin
Antidote: Protamine sulphatePoison: Iron salts
Antidote: DesferrioxaminePoison: Isoniazid
Antidote: PyridoxinePoison: Methanol
Antidotes: Ethanol, FomepizolePoison: Opioids
Antidote: NaloxonePoison: Organophosphates
Antidotes: Atropine, PralidoximePoison: Paracetamol
Antidotes: Acetylcysteine, MethioninePoison: Sulphonylureas
Antidotes: Glucose, OctreotidePoison: Thallium
Antidote: Prussian bluePoison: Warfarin
Antidote: Vitamin K, Fresh frozen plasma (FFP)By utilizing these specific antidotes, medical professionals can effectively counteract the harmful effects of various poisons and overdoses.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 14
Incorrect
-
A 32-year-old man with a known history of asthma presents with a headache, vomiting, and dizziness. His heart rate is elevated at 116 bpm. He currently takes a salbutamol inhaler and theophylline for his asthma. He had visited the Emergency Department a few days earlier and was prescribed an antibiotic.
Which antibiotic was most likely prescribed to this patient?Your Answer:
Correct Answer: Erythromycin
Explanation:Theophylline is a medication used to treat severe asthma. It is a bronchodilator that comes in modified-release forms, which can maintain therapeutic levels in the blood for 12 hours. Theophylline works by inhibiting phosphodiesterase and blocking the breakdown of cyclic AMP. It also competes with adenosine on A1 and A2 receptors.
Achieving the right dose of theophylline can be challenging because there is a narrow range between therapeutic and toxic levels. The half-life of theophylline can be influenced by various factors, further complicating dosage adjustments. It is recommended to aim for serum levels of 10-20 mg/l six to eight hours after the last dose.
Unlike many other medications, the specific brand of theophylline can significantly impact its effects. Therefore, it is important to prescribe theophylline by both its brand name and generic name.
Several factors can increase the half-life of theophylline, including heart failure, cirrhosis, viral infections, and certain drugs. Conversely, smoking, heavy drinking, and certain medications can decrease the half-life of theophylline.
There are several drugs that can either increase or decrease the plasma concentration of theophylline. Calcium channel blockers, cimetidine, fluconazole, macrolides, methotrexate, and quinolones can increase the concentration. On the other hand, carbamazepine, phenobarbitol, phenytoin, rifampicin, and St. John’s wort can decrease the concentration.
The clinical symptoms of theophylline toxicity are more closely associated with acute overdose rather than chronic overexposure. Common symptoms include headache, dizziness, nausea, vomiting, abdominal pain, rapid heartbeat, dysrhythmias, seizures, mild metabolic acidosis, low potassium, low magnesium, low phosphates, abnormal calcium levels, and high blood sugar.
Seizures are more prevalent in acute overdose cases, while chronic overdose typically presents with minimal gastrointestinal symptoms. Cardiac dysrhythmias are more common in chronic overdose situations compared to acute overdose.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 15
Incorrect
-
A 25 year old woman is brought to the emergency department by her roommate after intentionally overdosing on amitriptyline. What is a typical clinical sign of toxicity in this case?
Your Answer:
Correct Answer: Dilated pupils
Explanation:An overdose of Amitriptyline can lead to the development of an anticholinergic toxidrome. This toxidrome is characterized by various symptoms, which can be remembered using the phrase ‘mad as a hatter, hot as hell, red as a beat, dry as a bone, and blind as a bat’. Some of these symptoms include a dry mouth and an elevated body temperature.
Further Reading:
Tricyclic antidepressant (TCA) overdose is a common occurrence in emergency departments, with drugs like amitriptyline and dosulepin being particularly dangerous. TCAs work by inhibiting the reuptake of norepinephrine and serotonin in the central nervous system. In cases of toxicity, TCAs block various receptors, including alpha-adrenergic, histaminic, muscarinic, and serotonin receptors. This can lead to symptoms such as hypotension, altered mental state, signs of anticholinergic toxicity, and serotonin receptor effects.
TCAs primarily cause cardiac toxicity by blocking sodium and potassium channels. This can result in a slowing of the action potential, prolongation of the QRS complex, and bradycardia. However, the blockade of muscarinic receptors also leads to tachycardia in TCA overdose. QT prolongation and Torsades de Pointes can occur due to potassium channel blockade. TCAs can also have a toxic effect on the myocardium, causing decreased cardiac contractility and hypotension.
Early symptoms of TCA overdose are related to their anticholinergic properties and may include dry mouth, pyrexia, dilated pupils, agitation, sinus tachycardia, blurred vision, flushed skin, tremor, and confusion. Severe poisoning can lead to arrhythmias, seizures, metabolic acidosis, and coma. ECG changes commonly seen in TCA overdose include sinus tachycardia, widening of the QRS complex, prolongation of the QT interval, and an R/S ratio >0.7 in lead aVR.
Management of TCA overdose involves ensuring a patent airway, administering activated charcoal if ingestion occurred within 1 hour and the airway is intact, and considering gastric lavage for life-threatening cases within 1 hour of ingestion. Serial ECGs and blood gas analysis are important for monitoring. Intravenous fluids and correction of hypoxia are the first-line therapies. IV sodium bicarbonate is used to treat haemodynamic instability caused by TCA overdose, and benzodiazepines are the treatment of choice for seizure control. Other treatments that may be considered include glucagon, magnesium sulfate, and intravenous lipid emulsion.
There are certain things to avoid in TCA overdose, such as anti-arrhythmics like quinidine and flecainide, as they can prolonged depolarization.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 16
Incorrect
-
A 35-year-old patient with a history of schizophrenia comes in with side effects from haloperidol, which they were recently prescribed. Upon examination, you observe that they have significant muscle stiffness, a decreased level of consciousness, and a body temperature of 40ºC.
What side effect has manifested?Your Answer:
Correct Answer: Neuroleptic malignant syndrome
Explanation:First-generation antipsychotics, also known as conventional or typical antipsychotics, are powerful blockers of the dopamine D2 receptor. However, each drug in this category has different effects on other receptors, such as serotonin type 2 (5-HT2), alpha1, histaminic, and muscarinic receptors.
These first-generation antipsychotics are known to have a high incidence of extrapyramidal side effects, which include rigidity, bradykinesia, dystonias, tremor, akathisia, tardive dyskinesia, and neuroleptic malignant syndrome (NMS). NMS is a rare and life-threatening reaction to neuroleptic medications, characterized by fever, muscle stiffness, changes in mental state, and dysfunction of the autonomic nervous system. NMS typically occurs shortly after starting or increasing the dose of neuroleptic treatment.
On the other hand, second-generation antipsychotics, also referred to as novel or atypical antipsychotics, are dopamine D2 antagonists, except for aripiprazole. These medications are associated with lower rates of extrapyramidal side effects and NMS compared to the first-generation antipsychotics. However, they have higher rates of metabolic side effects and weight gain.
It is important to note that serotonin syndrome shares similar features with NMS but can be distinguished by the causative agent, most commonly the serotonin-specific reuptake inhibitors.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 17
Incorrect
-
A 14 year old boy is brought into the emergency department after being bitten on the leg while playing in the woods near his neighborhood. The patient claims that the bite was from a snake that he saw quickly disappear into the bushes after biting him. You present the patient with pictures of native snake species in the area, and the patient identifies the common Eastern garter snake as the culprit. Which of the following statements is accurate regarding the treatment of bites from this particular snake species?
Your Answer:
Correct Answer: The affected limb should immobilised in a sling
Explanation:The key components of first aid for snake bites in the UK involve immobilizing the patient and the affected limb, as well as administering paracetamol for pain relief. When it comes to venomous snake bites, it is important to immobilize the limb using a splint or sling, but not to use a tourniquet or pressure bandage for adder bites. In certain areas, such as NSW, Australia, where venomous snakes can cause rapidly progressing and life-threatening paralysis, pressure bandage immobilization is recommended. However, this is not the case in the UK. Anti-venom is not always necessary for adder bites, and its administration should be based on a thorough assessment of the patient’s condition and the presence of appropriate indications. Paracetamol is the preferred choice for pain relief in UK snake bites, as aspirin and ibuprofen can worsen bleeding tendencies that may result from adder bites. Similarly, heparin should be avoided for the same reason.
Further Reading:
Snake bites in the UK are primarily caused by the adder, which is the only venomous snake species native to the country. While most adder bites result in minor symptoms such as pain, swelling, and inflammation, there have been cases of life-threatening illness and fatalities. Additionally, there are instances where venomous snakes that are kept legally or illegally also cause bites in the UK.
Adder bites typically occur from early spring to late autumn, with the hand being the most common site of the bite. Symptoms can be local or systemic, with local symptoms including sharp pain, tingling or numbness, and swelling that spreads proximally. Systemic symptoms may include spreading pain, tenderness, inflammation, regional lymph node enlargement, and bruising. In severe cases, anaphylaxis can occur, leading to symptoms such as nausea, vomiting, abdominal pain, diarrhea, and shock.
It is important for clinicians to be aware of the potential complications and complications associated with adder bites. These can include acute renal failure, pulmonary and cerebral edema, acute gastric dilatation, paralytic ileus, acute pancreatitis, and coma and seizures. Anaphylaxis symptoms can appear within minutes or be delayed for hours, and hypotension is a critical sign to monitor.
Initial investigations for adder bites include blood tests, ECG, and vital sign monitoring. Further investigations such as chest X-ray may be necessary based on clinical signs. Blood tests may reveal abnormalities such as leukocytosis, raised hematocrit, anemia, thrombocytopenia, and abnormal clotting profile. ECG changes may include tachyarrhythmias, bradyarrhythmias, atrial fibrillation, and ST segment changes.
First aid measures at the scene include immobilizing the patient and the bitten limb, avoiding aspirin and ibuprofen, and cleaning the wound site in the hospital. Tetanus prophylaxis should be considered. In cases of anaphylaxis, prompt administration of IM adrenaline is necessary. In the hospital, rapid assessment and appropriate resuscitation with intravenous fluids are required.
Antivenom may be indicated in cases of hypotension, systemic envenoming, ECG abnormalities, peripheral neutrophil leucocytosis, elevated serum creatine kinase or metabolic acidosis, and extensive or rapidly spreading local swelling. Zagreb antivenom is commonly used in the UK, with an initial dose of 8 mL.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 18
Incorrect
-
A 30-year-old woman with a history of schizophrenia comes in with a side effect caused by the antipsychotic medication she is currently using.
Which ONE statement about the side effects of antipsychotic drugs is accurate?Your Answer:
Correct Answer: Haloperidol is the most common antipsychotic drug to cause extrapyramidal side effects
Explanation:Extrapyramidal side effects are most commonly seen with the piperazine phenothiazines (fluphenazine, prochlorperazine, and trifluoperazine) and butyrophenones (benperidol and haloperidol). Among these, haloperidol is the most frequently implicated antipsychotic drug.
Tardive dyskinesia, which involves rhythmic and involuntary movements of the tongue, face, and jaw, typically develops after long-term treatment or high doses. It is the most severe manifestation of extrapyramidal symptoms, as it may become irreversible even after discontinuing the causative drug, and treatment options are generally ineffective.
Dystonia, characterized by abnormal movements of the face and body, is more commonly observed in children and young adults and tends to occur after only a few doses. Acute dystonia can be managed with intravenous administration of procyclidine (5 mg) or benzatropine (2 mg) as a bolus.
Akathisia refers to an unpleasant sensation of restlessness, while akinesia refers to an inability to initiate movement.
Elderly patients with dementia-related psychosis who are treated with haloperidol have an increased risk of mortality. This is believed to be due to a higher likelihood of experiencing cardiovascular events and infections such as pneumonia.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 19
Incorrect
-
A 45-year-old woman is brought in by ambulance. She has ingested a significant amount of aspirin.
What type of acid-base imbalance would you anticipate to be present during the initial phases of an aspirin overdose?Your Answer:
Correct Answer: Respiratory alkalosis
Explanation:An overdose of aspirin often leads to a combination of respiratory alkalosis and metabolic acidosis. Initially, the stimulation of the respiratory center causes hyperventilation and results in respiratory alkalosis. However, as the overdose progresses, the direct acidic effects of aspirin cause an increase in the anion gap and metabolic acidosis.
Here is a summary of common causes for different acid-base disorders:
Respiratory alkalosis can be caused by hyperventilation due to factors such as anxiety, pulmonary embolism, CNS disorders (such as stroke or encephalitis), altitude, pregnancy, and the early stages of aspirin overdose.
Respiratory acidosis can occur in individuals with chronic obstructive pulmonary disease (COPD), life-threatening asthma, pulmonary edema, sedative drug overdose (such as opioids or benzodiazepines), neuromuscular diseases, and obesity.
Metabolic alkalosis can be caused by vomiting, potassium depletion (often due to diuretic usage), Cushing’s syndrome, and Conn’s syndrome.
Metabolic acidosis with a raised anion gap can result from conditions such as lactic acidosis (caused by factors like hypoxemia, shock, sepsis, or tissue infarction), ketoacidosis (associated with diabetes, starvation, or excessive alcohol consumption), renal failure, and poisoning (including the late stages of aspirin overdose, methanol or ethylene glycol ingestion).
Metabolic acidosis with a normal anion gap can be seen in renal tubular acidosis, diarrhea, ammonium chloride ingestion, and adrenal insufficiency.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 20
Incorrect
-
You review a 65-year-old woman who has been diagnosed with atrial fibrillation and is currently taking warfarin. She has developed an infection that needs to be treated with an antibiotic.
Which antibiotic would be the most suitable and safe option for this patient?Your Answer:
Correct Answer: Cefalexin
Explanation:The use of antibiotics can impact the effectiveness of warfarin and other coumarin anticoagulants. This can lead to changes in the International Normalized Ratio (INR) and, in severe cases, increase the risk of bleeding. Some antibiotics, such as chloramphenicol, ciprofloxacin, co-trimoxazole, doxycycline, erythromycin, macrolides (e.g., clarithromycin), metronidazole, ofloxacin, and sulphonamide, are known to enhance the anticoagulant effect of warfarin. However, cefalexin is considered relatively safe and is the most suitable option in this situation.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 21
Incorrect
-
A 22 year old student presents to the emergency department with a complaint of headache and nausea persisting for the last 24 hours. He reports feeling unwell shortly after he finished moving his belongings into his newly shared student accommodation. Carbon monoxide poisoning is suspected. What test will confirm the diagnosis?
Your Answer:
Correct Answer: Carboxyhaemoglobin
Explanation:Carboxyhaemoglobin (COHb) blood levels are utilized for the identification of carbon monoxide poisoning. COHb is the substance produced when carbon monoxide attaches to haemoglobin. It is important to note that carbaminohemoglobin (also known as carbaminohaemoglobin, carboxyhemoglobin, and carbohemoglobin) is the compound formed when carbon dioxide binds to hemoglobin, and should not be mistaken for COHb.
Further Reading:
Carbon monoxide (CO) is a dangerous gas that is produced by the combustion of hydrocarbon fuels and can be found in certain chemicals. It is colorless and odorless, making it difficult to detect. In England and Wales, there are approximately 60 deaths each year due to accidental CO poisoning.
When inhaled, carbon monoxide binds to haemoglobin in the blood, forming carboxyhaemoglobin (COHb). It has a higher affinity for haemoglobin than oxygen, causing a left-shift in the oxygen dissociation curve and resulting in tissue hypoxia. This means that even though there may be a normal level of oxygen in the blood, it is less readily released to the tissues.
The clinical features of carbon monoxide toxicity can vary depending on the severity of the poisoning. Mild or chronic poisoning may present with symptoms such as headache, nausea, vomiting, vertigo, confusion, and weakness. More severe poisoning can lead to intoxication, personality changes, breathlessness, pink skin and mucosae, hyperpyrexia, arrhythmias, seizures, blurred vision or blindness, deafness, extrapyramidal features, coma, or even death.
To help diagnose domestic carbon monoxide poisoning, there are four key questions that can be asked using the COMA acronym. These questions include asking about co-habitees and co-occupants in the house, whether symptoms improve outside of the house, the maintenance of boilers and cooking appliances, and the presence of a functioning CO alarm.
Typical carboxyhaemoglobin levels can vary depending on whether the individual is a smoker or non-smoker. Non-smokers typically have levels below 3%, while smokers may have levels below 10%. Symptomatic individuals usually have levels between 10-30%, and severe toxicity is indicated by levels above 30%.
When managing carbon monoxide poisoning, the first step is to administer 100% oxygen. Hyperbaric oxygen therapy may be considered for individuals with a COHb concentration of over 20% and additional risk factors such as loss of consciousness, neurological signs, myocardial ischemia or arrhythmia, or pregnancy. Other management strategies may include fluid resuscitation, sodium bicarbonate for metabolic acidosis, and mannitol for cerebral edema.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 22
Incorrect
-
A 35-year-old woman is given a medication during the advanced stages of pregnancy. As a result, the newborn experiences respiratory depression and develops a neonatal withdrawal syndrome.
Which of the following medications is the most probable cause of these abnormalities?Your Answer:
Correct Answer: Diazepam
Explanation:During the later stages of pregnancy, the use of diazepam has been linked to respiratory depression in newborns and a withdrawal syndrome. There are several drugs that can have adverse effects during pregnancy, and the list below outlines the most commonly encountered ones.
ACE inhibitors, such as ramipril, can cause hypoperfusion, renal failure, and the oligohydramnios sequence if given in the second and third trimesters. Aminoglycosides, like gentamicin, can lead to ototoxicity and deafness. High doses of aspirin can result in first-trimester abortions, delayed onset labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus. However, low doses (e.g., 75 mg) do not pose significant risks.
Benzodiazepines, including diazepam, can cause respiratory depression and a neonatal withdrawal syndrome when administered late in pregnancy. Calcium-channel blockers can cause phalangeal abnormalities if given in the first trimester and fetal growth retardation if given in the second and third trimesters. Carbamazepine can lead to hemorrhagic disease of the newborn and neural tube defects.
Chloramphenicol is associated with grey baby syndrome. Corticosteroids, if given in the first trimester, may cause orofacial clefts. Danazol, when administered in the first trimester, can cause masculinization of the female fetuses genitals. Pregnant women should avoid handling crushed or broken tablets of finasteride as it can affect male sex organ development.
Haloperidol, if given in the first trimester, may cause limb malformations. In the third trimester, there is an increased risk of extrapyramidal symptoms in the neonate. Heparin can lead to maternal bleeding and thrombocytopenia. Isoniazid can cause maternal liver damage and neuropathy and seizures in the neonate. Isotretinoin carries a high risk of teratogenicity, including multiple congenital malformations, spontaneous abortion, and intellectual disability.
Lithium, if given in the first trimester, poses a risk of fetal cardiac malformations. In the second and third trimesters, it can result in hypotonia, lethargy, feeding problems, hypothyroidism, goiter, and nephrogenic diabetes insipidus in the neonate.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 23
Incorrect
-
A 45 year old woman is brought into the emergency department after intentionally overdosing on a significant amount of amitriptyline following the end of a relationship. You order an ECG. What ECG changes are commonly seen in cases of amitriptyline overdose?
Your Answer:
Correct Answer: Prolongation of QRS
Explanation:TCA toxicity can be identified through specific changes seen on an electrocardiogram (ECG). Sinus tachycardia, which is a faster than normal heart rate, and widening of the QRS complex are key features of TCA toxicity. These ECG changes occur due to the blocking of sodium channels and muscarinic receptors (M1) by the medication. In the case of an amitriptyline overdose, additional ECG changes may include prolongation of the QT interval, an R/S ratio greater than 0.7 in lead aVR, and the presence of ventricular arrhythmias such as torsades de pointes. The severity of the QRS prolongation on the ECG is associated with the likelihood of adverse events. A QRS duration greater than 100 ms is predictive of seizures, while a QRS duration greater than 160 ms is predictive of ventricular arrhythmias like ventricular tachycardia or torsades de pointes.
Further Reading:
Tricyclic antidepressant (TCA) overdose is a common occurrence in emergency departments, with drugs like amitriptyline and dosulepin being particularly dangerous. TCAs work by inhibiting the reuptake of norepinephrine and serotonin in the central nervous system. In cases of toxicity, TCAs block various receptors, including alpha-adrenergic, histaminic, muscarinic, and serotonin receptors. This can lead to symptoms such as hypotension, altered mental state, signs of anticholinergic toxicity, and serotonin receptor effects.
TCAs primarily cause cardiac toxicity by blocking sodium and potassium channels. This can result in a slowing of the action potential, prolongation of the QRS complex, and bradycardia. However, the blockade of muscarinic receptors also leads to tachycardia in TCA overdose. QT prolongation and Torsades de Pointes can occur due to potassium channel blockade. TCAs can also have a toxic effect on the myocardium, causing decreased cardiac contractility and hypotension.
Early symptoms of TCA overdose are related to their anticholinergic properties and may include dry mouth, pyrexia, dilated pupils, agitation, sinus tachycardia, blurred vision, flushed skin, tremor, and confusion. Severe poisoning can lead to arrhythmias, seizures, metabolic acidosis, and coma. ECG changes commonly seen in TCA overdose include sinus tachycardia, widening of the QRS complex, prolongation of the QT interval, and an R/S ratio >0.7 in lead aVR.
Management of TCA overdose involves ensuring a patent airway, administering activated charcoal if ingestion occurred within 1 hour and the airway is intact, and considering gastric lavage for life-threatening cases within 1 hour of ingestion. Serial ECGs and blood gas analysis are important for monitoring. Intravenous fluids and correction of hypoxia are the first-line therapies. IV sodium bicarbonate is used to treat haemodynamic instability caused by TCA overdose, and benzodiazepines are the treatment of choice for seizure control. Other treatments that may be considered include glucagon, magnesium sulfate, and intravenous lipid emulsion.
There are certain things to avoid in TCA overdose, such as anti-arrhythmics like quinidine and flecainide, as they can prolonged depolarization. Amiodarone should
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 24
Incorrect
-
A 45-year-old male patient comes in with loss of appetite, vomiting, fatigue, and disorientation. His blood tests show low sodium levels, and after further examination, he is diagnosed with drug-induced syndrome of inappropriate antidiuretic hormone secretion (SIADH).
Which of the following medications is most likely causing this presentation?Your Answer:
Correct Answer: Amitriptyline
Explanation:The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is characterized by the presence of low sodium levels and low osmolality due to the inappropriate and continuous release or action of the hormone, despite normal or increased blood volume. This leads to a decreased ability to excrete water.
There are several factors that can cause SIADH, with carbamazepine being a well-known example. These causes can be grouped into different categories. One category is CNS damage, which includes conditions like meningitis and subarachnoid hemorrhage. Another category is malignancy, with small-cell lung cancer being a common cause. Certain drugs, such as carbamazepine, SSRIs, amitriptyline, and morphine, can also trigger SIADH. Infections, such as pneumonia, lung abscess, and brain abscess, are another potential cause. Lastly, endocrine disorders like hypothyroidism can contribute to the development of SIADH. -
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 25
Incorrect
-
A 25-year-old man is brought to the Emergency Department by his friend following taking an overdose of one of his prescribed medications. He is agitated, confused and is experiencing visual hallucinations. His heart rate is currently 110 bpm, and his pupils are dilated. It is difficult to obtain a history from him as he is mumbling. You also note that he appears flushed and his skin is warm to the touch.
Which of the following drugs is most likely to be responsible?Your Answer:
Correct Answer: Chlorpromazine
Explanation:This patient exhibits clinical features that are consistent with the ingestion of a drug that blocks the action of the neurotransmitter acetylcholine in the central and peripheral nervous system. There are several anticholinergic drugs commonly used in clinical practice. Some examples include antihistamines like promethazine and diphenhydramine, typical and atypical antipsychotics such as haloperidol and quetiapine, anticonvulsants like carbamazepine, antidepressants like tricyclic antidepressants, and antispasmodics like hyoscine butylbromide. Other sources of anticholinergic effects can come from plants like datura species and certain mushrooms.
When someone ingests an anticholinergic drug, they may experience a toxidrome, which is characterized by an agitated delirium and various signs of acetylcholine receptor blockade in both the central and peripheral nervous system. The central inhibition leads to an agitated delirium, which is marked by fluctuating mental status, confusion, restlessness, visual hallucinations, picking at objects in the air, mumbling, slurred speech, disruptive behavior, tremor, myoclonus, and in rare cases, coma and seizures. The peripheral inhibition can cause dilated pupils, sinus tachycardia, dry mouth, hot and flushed skin, increased body temperature, urinary retention, and ileus.
In summary, the ingestion of an anticholinergic drug can result in a toxidrome characterized by an agitated delirium and various signs of central and peripheral acetylcholine receptor blockade. It is important to be aware of the potential effects of these drugs and to recognize the clinical features associated with their ingestion.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 26
Incorrect
-
A 35-year-old man with a history of bipolar affective disorder presents with symptoms suggestive of lithium toxicity.
Which of the following symptoms is LEAST likely to be observed?Your Answer:
Correct Answer: SIADH
Explanation:SIADH is a medical condition that is not brought on by lithium toxicity. However, lithium toxicity does have its own distinct set of symptoms. These symptoms include nausea and vomiting, diarrhea, tremors, ataxia, confusion, increased muscle tone, clonus, nephrogenic diabetes insipidus, convulsions, coma, and renal failure. It is important to note that SIADH and lithium toxicity are separate conditions with their own unique characteristics.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 27
Incorrect
-
You are informed that a 45-year-old individual is en route to the emergency department after inhaling an unidentified gas that was intentionally released on a commuter train. Authorities suspect a potential terrorist attack and recommend checking the patient for signs of organophosphate poisoning. What clinical feature would be anticipated in a case of organophosphate poisoning?
Your Answer:
Correct Answer: Drooling saliva
Explanation:Organophosphate poisoning is characterized by a set of symptoms known as SLUDGE (Salivation, Lacrimation, Urination, Defecation, Gastric cramps, Emesis). Additionally, individuals affected may experience pinpoint pupils, profuse sweating, tremors, and confusion. Organophosphates serve as the foundation for various weaponized nerve agents like Sarin and VX, which were infamously employed by the terrorist group Aum Shinrikyo during multiple attacks in Tokyo in the mid-1990s. While SLUDGE is a commonly used acronym to recall the clinical features, it is important to note that other symptoms such as pinpoint pupils, profuse sweating, tremors, and confusion are not included in the acronym.
Further Reading:
Chemical incidents can occur as a result of leaks, spills, explosions, fires, terrorism, or the use of chemicals during wars. Industrial sites that use chemicals are required to conduct risk assessments and have accident plans in place for such incidents. Health services are responsible for decontamination, unless mass casualties are involved, and all acute health trusts must have major incident plans in place.
When responding to a chemical incident, hospitals prioritize containment of the incident and prevention of secondary contamination, triage with basic first aid, decontamination if not done at the scene, recognition and management of toxidromes (symptoms caused by exposure to specific toxins), appropriate supportive or antidotal treatment, transfer to definitive treatment, a safe end to the hospital response, and continuation of business after the event.
To obtain advice when dealing with chemical incidents, the two main bodies are Toxbase and the National Poisons Information Service. Signage on containers carrying chemicals and material safety data sheets (MSDS) accompanying chemicals also provide information on the chemical contents and their hazards.
Contamination in chemical incidents can occur in three phases: primary contamination from the initial incident, secondary contamination spread via contaminated people leaving the initial scene, and tertiary contamination spread to the environment, including becoming airborne and waterborne. The ideal personal protective equipment (PPE) for chemical incidents is an all-in-one chemical-resistant overall with integral head/visor and hands/feet worn with a mask, gloves, and boots.
Decontamination of contaminated individuals involves the removal and disposal of contaminated clothing, followed by either dry or wet decontamination. Dry decontamination is suitable for patients contaminated with non-caustic chemicals and involves blotting and rubbing exposed skin gently with dry absorbent material. Wet decontamination is suitable for patients contaminated with caustic chemicals and involves a warm water shower while cleaning the body with simple detergent.
After decontamination, the focus shifts to assessing the extent of any possible poisoning and managing it. The patient’s history should establish the chemical the patient was exposed to, the volume and concentration of the chemical, the route of exposure, any protective measures in place, and any treatment given. Most chemical poisonings require supportive care using standard resuscitation principles, while some chemicals have specific antidotes. Identifying toxidromes can be useful in guiding treatment, and specific antidotes may be administered accordingly.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 28
Incorrect
-
A 35-year-old woman is given diclofenac for arthritis during her second trimester of pregnancy. As a result of this medication, the baby develops a birth defect.
What is the most probable birth defect that can occur due to the use of diclofenac during pregnancy?Your Answer:
Correct Answer: Premature closure of the ductus arteriosus
Explanation:The use of NSAIDs during the third trimester of pregnancy is associated with several risks. These risks include delayed onset of labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus, which is a condition characterized by bilirubin-induced brain dysfunction. Additionally, there is a slight increase in the risk of first-trimester abortion if NSAIDs are used early in pregnancy.
Below is a list outlining the most commonly encountered drugs that have adverse effects during pregnancy:
Drug: ACE inhibitors (e.g. ramipril)
Adverse effects: If given in the second and third trimester, ACE inhibitors can cause hypoperfusion, renal failure, and the oligohydramnios sequence.Drug: Aminoglycosides (e.g. gentamicin)
Adverse effects: Aminoglycosides can cause ototoxicity, leading to deafness in the fetus.Drug: Aspirin
Adverse effects: High doses of aspirin can cause first-trimester abortions, delayed onset of labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus. However, low doses (e.g. 75 mg) have no significant associated risk.Drug: Benzodiazepines (e.g. diazepam)
Adverse effects: When given late in pregnancy, benzodiazepines can cause respiratory depression and a neonatal withdrawal syndrome.Drug: Calcium-channel blockers
Adverse effects: If given in the first trimester, calcium-channel blockers can cause phalangeal abnormalities. If given in the second and third trimester, they can cause fetal growth retardation. -
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 29
Incorrect
-
A 22-year-old arrives at the emergency department after ingesting a combination of pills following a heated dispute with their partner. The patient reports consuming approximately 30 tablets of various types, which were obtained from their partner's grandparents. However, the patient is unaware of the specific names of the tablets. You contemplate administering activated charcoal. What accurately describes the mechanism of action of activated charcoal?
Your Answer:
Correct Answer: Absorbs poisons onto its surface by weak electrostatic forces
Explanation:Activated charcoal prevents the absorption of poisons by absorbing them onto its surface through weak electrostatic forces.
Further Reading:
Poisoning in the emergency department is often caused by accidental or intentional overdose of prescribed drugs. Supportive treatment is the primary approach for managing most poisonings. This includes ensuring a clear airway, proper ventilation, maintaining normal fluid levels, temperature, and blood sugar levels, correcting any abnormal blood chemistry, controlling seizures, and assessing and treating any injuries.
In addition to supportive treatment, clinicians may need to consider strategies for decontamination, elimination, and administration of antidotes. Decontamination involves removing poisons from the skin or gastrointestinal tract. This can be done through rinsing the skin or using methods such as activated charcoal, gastric lavage, induced emesis, or whole bowel irrigation. However, induced emesis is no longer commonly used, while gastric lavage and whole bowel irrigation are rarely used.
Elimination methods include urinary alkalinization, hemodialysis, and hemoperfusion. These techniques help remove toxins from the body.
Activated charcoal is a commonly used method for decontamination. It works by binding toxins in the gastrointestinal tract, preventing their absorption. It is most effective if given within one hour of ingestion. However, it is contraindicated in patients with an insecure airway due to the risk of aspiration. Activated charcoal can be used for many drugs, but it is ineffective for certain poisonings, including pesticides (organophosphates), hydrocarbons, strong acids and alkalis, alcohols (ethanol, methanol, ethylene glycol), iron, lithium, and solvents.
Antidotes are specific treatments for poisoning caused by certain drugs or toxins. For example, cyanide poisoning can be treated with dicobalt edetate, hydroxocobalamin, or sodium nitrite and sodium thiosulphate. Benzodiazepine poisoning can be treated with flumazanil, while opiate poisoning can be treated with naloxone. Other examples include protamine for heparin poisoning, vitamin K or fresh frozen plasma for warfarin poisoning, fomepizole or ethanol for methanol poisoning, and methylene blue for methemoglobinemia caused by benzocaine or nitrates.
There are many other antidotes available for different types of poisoning, and resources such as TOXBASE and the National Poisons Information Service (NPIS) can provide valuable advice on managing poisonings.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 30
Incorrect
-
A 42-year-old man is brought into the emergency department with suspected methanol poisoning. You collect a blood gas sample. What acid-base disturbance is commonly associated with methanol poisoning?
Your Answer:
Correct Answer: Raised anion gap acidosis
Explanation:Methanol poisoning is linked to an increase in anion gap acidosis.
Further Reading:
Arterial blood gases (ABG) are an important diagnostic tool used to assess a patient’s acid-base status and respiratory function. When obtaining an ABG sample, it is crucial to prioritize safety measures to minimize the risk of infection and harm to the patient. This includes performing hand hygiene before and after the procedure, wearing gloves and protective equipment, disinfecting the puncture site with alcohol, using safety needles when available, and properly disposing of equipment in sharps bins and contaminated waste bins.
To reduce the risk of harm to the patient, it is important to test for collateral circulation using the modified Allen test for radial artery puncture. Additionally, it is essential to inquire about any occlusive vascular conditions or anticoagulation therapy that may affect the procedure. The puncture site should be checked for signs of infection, injury, or previous surgery. After the test, pressure should be applied to the puncture site or the patient should be advised to apply pressure for at least 5 minutes to prevent bleeding.
Interpreting ABG results requires a systematic approach. The core set of results obtained from a blood gas analyser includes the partial pressures of oxygen and carbon dioxide, pH, bicarbonate concentration, and base excess. These values are used to assess the patient’s acid-base status.
The pH value indicates whether the patient is in acidosis, alkalosis, or within the normal range. A pH less than 7.35 indicates acidosis, while a pH greater than 7.45 indicates alkalosis.
The respiratory system is assessed by looking at the partial pressure of carbon dioxide (pCO2). An elevated pCO2 contributes to acidosis, while a low pCO2 contributes to alkalosis.
The metabolic aspect is assessed by looking at the bicarbonate (HCO3-) level and the base excess. A high bicarbonate concentration and base excess indicate alkalosis, while a low bicarbonate concentration and base excess indicate acidosis.
Analyzing the pCO2 and base excess values can help determine the primary disturbance and whether compensation is occurring. For example, a respiratory acidosis (elevated pCO2) may be accompanied by metabolic alkalosis (elevated base excess) as a compensatory response.
The anion gap is another important parameter that can help determine the cause of acidosis. It is calculated by subtracting the sum of chloride and bicarbonate from the sum of sodium and potassium.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 31
Incorrect
-
A 45-year-old with a history of bipolar disorder is brought into the emergency department after intentionally taking an excessive amount of lithium. What acid-base disturbances would you anticipate in a patient who has overdosed on lithium?
Your Answer:
Correct Answer: Low anion gap acidosis
Explanation:Excessive intake of lithium is linked to the development of low anion gap acidosis. In cases of lithium overdose, a common outcome is the occurrence of low anion gap acidosis.
Further Reading:
Arterial blood gases (ABG) are an important diagnostic tool used to assess a patient’s acid-base status and respiratory function. When obtaining an ABG sample, it is crucial to prioritize safety measures to minimize the risk of infection and harm to the patient. This includes performing hand hygiene before and after the procedure, wearing gloves and protective equipment, disinfecting the puncture site with alcohol, using safety needles when available, and properly disposing of equipment in sharps bins and contaminated waste bins.
To reduce the risk of harm to the patient, it is important to test for co-lateral circulation using the modified Allen test for radial artery puncture. Additionally, it is essential to inquire about any occlusive vascular conditions or anticoagulation therapy that may affect the procedure. The puncture site should be checked for signs of infection, injury, or previous surgery. After the test, pressure should be applied to the puncture site or the patient should be advised to apply pressure for at least 5 minutes to prevent bleeding.
Interpreting ABG results requires a systematic approach. The core set of results obtained from a blood gas analyser includes the partial pressures of oxygen and carbon dioxide, pH, bicarbonate concentration, and base excess. These values are used to assess the patient’s acid-base status.
The pH value indicates whether the patient is in acidosis, alkalosis, or within the normal range. A pH less than 7.35 indicates acidosis, while a pH greater than 7.45 indicates alkalosis.
The respiratory system is assessed by looking at the partial pressure of carbon dioxide (pCO2). An elevated pCO2 contributes to acidosis, while a low pCO2 contributes to alkalosis.
The metabolic aspect is assessed by looking at the bicarbonate (HCO3-) level and the base excess. A high bicarbonate concentration and base excess indicate alkalosis, while a low bicarbonate concentration and base excess indicate acidosis.
Analyzing the pCO2 and base excess values can help determine the primary disturbance and whether compensation is occurring. For example, a respiratory acidosis (elevated pCO2) may be accompanied by metabolic alkalosis (elevated base excess) as a compensatory response.
The anion gap is another important parameter that can help determine the cause of acidosis. It is calculated by subtracting the sum of chloride and bicarbonate from the sum of sodium and potassium.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 32
Incorrect
-
A 72-year-old woman with a history of hypertension and kidney disease is prescribed a new diuretic medication. Upon reviewing her blood test results, you observe the presence of hyperkalemia.
Which of the following diuretics is most likely to be the cause?Your Answer:
Correct Answer: Spironolactone
Explanation:Spironolactone is a medication used to treat conditions such as congestive cardiac failure, hypertension, hepatic cirrhosis with ascites and edema, and Conn’s syndrome. It functions as a competitive aldosterone receptor antagonist, primarily working in the distal convoluted tubule. In this area, it hinders the reabsorption of sodium ions and enhances the reabsorption of potassium ions. Spironolactone is commonly known as a potassium-sparing diuretic.
The main side effect of spironolactone is hyperkalemia, particularly when renal impairment is present. In severe cases, hyperkalemia can be life-threatening. Additionally, there is a notable occurrence of gastrointestinal disturbances, with nausea and vomiting being the most common. Women may experience menstrual disturbances, while men may develop gynecomastia, both of which are attributed to the antiandrogenic effects of spironolactone.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 33
Incorrect
-
A 52-year-old woman with a history of hypertension has ingested an excessive amount of atenolol tablets.
Which of the following antidotes is appropriate for treating beta-blocker overdose?Your Answer:
Correct Answer: Insulin
Explanation:There are various specific remedies available for different types of poisons and overdoses. The following list provides an outline of some of these antidotes:
Poison: Benzodiazepines
Antidote: FlumazenilPoison: Beta-blockers
Antidotes: Atropine, Glucagon, InsulinPoison: Carbon monoxide
Antidote: OxygenPoison: Cyanide
Antidotes: Hydroxocobalamin, Sodium nitrite, Sodium thiosulphatePoison: Ethylene glycol
Antidotes: Ethanol, FomepizolePoison: Heparin
Antidote: Protamine sulphatePoison: Iron salts
Antidote: DesferrioxaminePoison: Isoniazid
Antidote: PyridoxinePoison: Methanol
Antidotes: Ethanol, FomepizolePoison: Opioids
Antidote: NaloxonePoison: Organophosphates
Antidotes: Atropine, PralidoximePoison: Paracetamol
Antidotes: Acetylcysteine, MethioninePoison: Sulphonylureas
Antidotes: Glucose, OctreotidePoison: Thallium
Antidote: Prussian bluePoison: Warfarin
Antidote: Vitamin K, Fresh frozen plasma (FFP)By utilizing these specific antidotes, medical professionals can effectively counteract the harmful effects of various poisons and overdoses.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 34
Incorrect
-
A 25-year-old woman is brought to the Emergency Department 'resus' area by ambulance after collapsing due to heroin use. She has pinpoint pupils, a respiratory rate of 5 per minute, and a GCS of 6/15.
What drug treatment should she be given?Your Answer:
Correct Answer: Naloxone 400 mcg IV
Explanation:Opioid poisoning is a common occurrence in the Emergency Department. It can occur as a result of recreational drug use, such as heroin, or from prescribed opioids like morphine sulfate tablets or dihydrocodeine.
The symptoms of opioid overdose include a decreased level of consciousness or even coma, reduced respiratory rate, apnea, pinpoint pupils, low blood pressure, cyanosis, convulsions, and non-cardiogenic pulmonary edema (in cases of intravenous heroin usage). The most common cause of death from opioid overdose is respiratory depression, which typically happens within an hour of the overdose. Vomiting is also common, and there is a risk of aspiration.
Naloxone is the specific antidote for opioid overdose. It can reverse respiratory depression and coma if given in sufficient dosage. The initial intravenous dose is 400 micrograms, followed by 800 micrograms for up to two doses at one-minute intervals if there is no response to the preceding dose. If there is still no response, the dose may be increased to 2 mg for one dose (seriously poisoned patients may require a 4 mg dose). If the intravenous route is not feasible, naloxone can be given by intramuscular injection.
Since naloxone has a shorter duration of action than most opioids, close monitoring and repeated injections are necessary. The dosage should be adjusted based on the respiratory rate and depth of coma. Generally, the dose is repeated every 2-3 minutes, up to a maximum of 10 mg. In cases where repeated doses are needed, naloxone can be administered through a continuous infusion, with the infusion rate initially set at 60% of the initial resuscitative intravenous dose per hour.
In opioid addicts, the administration of naloxone may trigger a withdrawal syndrome, characterized by abdominal cramps, nausea, and diarrhea. However, these symptoms typically subside within 2 hours.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 35
Incorrect
-
A 35-year-old patient with a history of schizophrenia comes in with side effects from a medication that he recently began taking for this condition. Upon examination, you observe that he is experiencing severe muscular rigidity, a decreased level of consciousness, and a body temperature of 40ºC.
Which of the following medications is most likely causing these symptoms?Your Answer:
Correct Answer: Chlorpromazine
Explanation:First-generation antipsychotics, also known as conventional or typical antipsychotics, are potent blockers of dopamine D2 receptors. However, these drugs also have varying effects on other receptors such as serotonin type 2 (5-HT2), alpha1, histaminic, and muscarinic receptors.
One of the major drawbacks of first-generation antipsychotics is their high incidence of extrapyramidal side effects. These include rigidity, bradykinesia, dystonias, tremor, akathisia, and tardive dyskinesia. Additionally, there is a rare but life-threatening reaction called neuroleptic malignant syndrome (NMS) that can occur with these medications. NMS is characterized by fever, muscle rigidity, altered mental status, and autonomic dysfunction. It typically occurs shortly after starting or increasing the dose of a neuroleptic medication.
In contrast, second-generation antipsychotics, also known as novel or atypical antipsychotics, have a lower risk of extrapyramidal side effects and NMS compared to their first-generation counterparts. However, they are associated with higher rates of metabolic effects and weight gain.
It is important to differentiate serotonin syndrome from NMS as they share similar features. Serotonin syndrome is most commonly caused by serotonin-specific reuptake inhibitors.
Here are some commonly encountered examples of first- and second-generation antipsychotics:
First-generation:
– Chlopromazine
– Haloperidol
– Fluphenazine
– TrifluoperazineSecond-generation:
– Clozapine
– Olanzapine
– Quetiapine
– Risperidone
– Aripiprazole -
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 36
Incorrect
-
A 72-year-old woman has been referred to the Emergency Department by her primary care physician after a review of her digoxin prescription. Her physician reports that her current digoxin levels are elevated.
At what digoxin level is toxicity typically observed?Your Answer:
Correct Answer: 2 nmol/L
Explanation:Digoxin is a medication used to manage heart failure and atrial fibrillation. It works by inhibiting the Na+/K+ ATPase in the myocardium, which slows down the ventricular response and has a positive effect on the heart’s contraction. Although less commonly used nowadays, digoxin still plays a role in certain cases.
One advantage of digoxin is its long half-life, allowing for once-daily maintenance doses. However, it is important to monitor the dosage to ensure it is correct and to watch out for factors that may lead to toxicity, such as renal dysfunction and hypokalemia. Once a steady state has been achieved, regular monitoring of plasma digoxin concentrations is not necessary unless there are concerns.
In atrial fibrillation, the effectiveness of digoxin treatment is best assessed by monitoring the ventricular rate. The target range for plasma digoxin concentration is 1.0-1.5 nmol/L, although higher levels of up to 2 nmol/L may be needed in some cases. It is important to note that the plasma concentration alone cannot reliably indicate toxicity, but levels above 2 nmol/L significantly increase the risk. To manage hypokalemia, which can increase the risk of digoxin toxicity, a potassium-sparing diuretic or potassium supplementation may be prescribed.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 37
Incorrect
-
A 25-year-old man is given a medication for a health condition during the 2nd trimester of his partner's pregnancy. As a result, the newborn developed kernicterus and early closure of the ductus arteriosus.
Which of the following medications is the most probable cause of these abnormalities?Your Answer:
Correct Answer: Aspirin
Explanation:The use of low-dose aspirin during pregnancy is considered safe and can be used to manage recurrent miscarriage, clotting disorders, and pre-eclampsia. On the other hand, high-dose aspirin carries several risks, especially if used in the third trimester. These risks include delayed onset of labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus (a condition that affects the brain due to high levels of bilirubin). Additionally, there is a slight increase in the risk of first-trimester abortion if high-dose aspirin is used early in pregnancy.
Below is a list outlining commonly encountered drugs that have adverse effects during pregnancy:
Drug: ACE inhibitors (e.g. ramipril)
Adverse effects: If given in the second and third trimester, ACE inhibitors can cause hypoperfusion, renal failure, and the oligohydramnios sequence.Drug: Aminoglycosides (e.g. gentamicin)
Adverse effects: Aminoglycosides can cause ototoxicity (damage to the ear) and deafness.Drug: Aspirin
Adverse effects: High doses of aspirin can cause first-trimester abortions, delayed onset of labor, premature closure of the fetal ductus arteriosus, and fetal kernicterus. However, low doses (e.g. 75 mg) have no significant associated risk. -
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 38
Incorrect
-
A 35-year-old woman comes in with a worsening of her asthma symptoms. She has been experiencing heart palpitations and decided to self-medicate with one of her sister's heart medications. Shortly after taking the medication, her asthma symptoms worsened.
Which of the following medications is most likely to have caused her asthma exacerbation?Your Answer:
Correct Answer: Propranolol
Explanation:Non-selective beta-blockers, like propranolol, can cause severe bronchospasm in individuals with asthma, particularly when taken in high doses. The current guidelines from the British Thoracic Society (BTS) recommend avoiding the use of beta-blockers in asthma patients. However, there is some evidence suggesting that the long-term use of cardioselective beta-blockers does not appear to trigger asthma attacks in individuals with mild or moderate asthma.
Beta-blockers play a crucial role in the treatment of patients who have a history of previous myocardial infarction or systolic dysfunction. In individuals with asthma and one of these diagnoses, it is unlikely that the potential benefits of beta-blockers outweigh the risks of worsening asthma symptoms.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 39
Incorrect
-
A 42 year old man visits the emergency department. He had a mishap and fell into a glass window, resulting in a significant cut on his left forearm. You suggest that this can be stitched up using local anesthesia. What is the highest dosage of lidocaine with adrenaline that can be administered for this procedure?
Your Answer:
Correct Answer: 7 mg/kg
Explanation:The recommended dose of adrenaline is 7 mg per kilogram of body weight, with a maximum limit of 500 mg.
Local anaesthetics, such as lidocaine, bupivacaine, and prilocaine, are commonly used in the emergency department for topical or local infiltration to establish a field block. Lidocaine is often the first choice for field block prior to central line insertion. These anaesthetics work by blocking sodium channels, preventing the propagation of action potentials.
However, local anaesthetics can enter the systemic circulation and cause toxic side effects if administered in high doses. Clinicians must be aware of the signs and symptoms of local anaesthetic systemic toxicity (LAST) and know how to respond. Early signs of LAST include numbness around the mouth or tongue, metallic taste, dizziness, visual and auditory disturbances, disorientation, and drowsiness. If not addressed, LAST can progress to more severe symptoms such as seizures, coma, respiratory depression, and cardiovascular dysfunction.
The management of LAST is largely supportive. Immediate steps include stopping the administration of local anaesthetic, calling for help, providing 100% oxygen and securing the airway, establishing IV access, and controlling seizures with benzodiazepines or other medications. Cardiovascular status should be continuously assessed, and conventional therapies may be used to treat hypotension or arrhythmias. Intravenous lipid emulsion (intralipid) may also be considered as a treatment option.
If the patient goes into cardiac arrest, CPR should be initiated following ALS arrest algorithms, but lidocaine should not be used as an anti-arrhythmic therapy. Prolonged resuscitation may be necessary, and intravenous lipid emulsion should be administered. After the acute episode, the patient should be transferred to a clinical area with appropriate equipment and staff for further monitoring and care.
It is important to report cases of local anaesthetic toxicity to the appropriate authorities, such as the National Patient Safety Agency in the UK or the Irish Medicines Board in the Republic of Ireland. Additionally, regular clinical review should be conducted to exclude pancreatitis, as intravenous lipid emulsion can interfere with amylase or lipase assays.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 40
Incorrect
-
A 65-year-old patient with a past medical history of chronic congestive cardiac failure complains of feeling fatigued and generally not well. She is currently on high doses of furosemide as prescribed by her heart failure specialist. Upon reviewing her blood test results, you observe that her electrolyte levels are abnormal.
Which of the following electrolyte imbalances is most likely to be present?Your Answer:
Correct Answer: Low sodium, low potassium
Explanation:Loop diuretics, like furosemide, commonly result in several electrolyte imbalances. These imbalances include hyponatremia, which is a decrease in sodium levels in the blood. Another common imbalance is hypokalemia, which refers to low levels of potassium. Additionally, loop diuretics can cause hypocalcemia, a condition characterized by low levels of calcium in the blood. Another electrolyte affected by loop diuretics is magnesium, as they can lead to hypomagnesemia, which is a deficiency of magnesium. Lastly, loop diuretics can cause hypochloremic alkalosis, which is a condition characterized by low levels of chloride in the blood and an increase in blood pH.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 41
Incorrect
-
A 45-year-old woman develops hypothyroidism secondary to the administration of a medication for a thyroid condition.
Which of the following medications is most likely to be responsible?Your Answer:
Correct Answer: Amiodarone
Explanation:Amiodarone has a chemical structure that is similar to thyroxine and has the ability to bind to the nuclear thyroid receptor. This medication has the potential to cause both hypothyroidism and hyperthyroidism, although hypothyroidism is more commonly observed, affecting around 5-10% of patients.
There are several side effects associated with the use of amiodarone. These include the formation of microdeposits in the cornea, increased sensitivity to sunlight resulting in photosensitivity, feelings of nausea, disturbances in sleep patterns, and the development of either hyperthyroidism or hypothyroidism. In addition, there have been reported cases of acute hepatitis and jaundice, peripheral neuropathy, lung fibrosis, and QT prolongation.
It is important to be aware of these potential side effects when considering the use of amiodarone as a treatment option. Regular monitoring and close medical supervision are necessary to detect and manage any adverse reactions that may occur.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 42
Incorrect
-
You are following up on a 21-year-old patient you saw who was admitted following a paracetamol overdose. Which of the following is a poor prognostic indicator and indication for liver transplant in paracetamol overdose?
Your Answer:
Correct Answer:
Explanation:A pH level in the arteries that is below 7.30 on or after the second day following a paracetamol overdose is considered a poor indicator of prognosis. Additionally, a prolonged prothrombin time (PT) of over 100 seconds (indicated by an international normalized ratio (INR) of over 6.5), along with a high plasma creatinine level of over 300 μmol/L and grade 3 or 4 hepatic encephalopathy, are also poor prognostic indicators and may indicate the need for a liver transplant. Furthermore, an increase in PT between the third and fourth day after the overdose is also considered a poor prognostic indicator.
Further Reading:
Paracetamol poisoning occurs when the liver is unable to metabolize paracetamol properly, leading to the production of a toxic metabolite called N-acetyl-p-benzoquinone imine (NAPQI). Normally, NAPQI is conjugated by glutathione into a non-toxic form. However, during an overdose, the liver’s conjugation systems become overwhelmed, resulting in increased production of NAPQI and depletion of glutathione stores. This leads to the formation of covalent bonds between NAPQI and cell proteins, causing cell death in the liver and kidneys.
Symptoms of paracetamol poisoning may not appear for the first 24 hours or may include abdominal symptoms such as nausea and vomiting. After 24 hours, hepatic necrosis may develop, leading to elevated liver enzymes, right upper quadrant pain, and jaundice. Other complications can include encephalopathy, oliguria, hypoglycemia, renal failure, and lactic acidosis.
The management of paracetamol overdose depends on the timing and amount of ingestion. Activated charcoal may be given if the patient presents within 1 hour of ingesting a significant amount of paracetamol. N-acetylcysteine (NAC) is used to increase hepatic glutathione production and is given to patients who meet specific criteria. Blood tests are taken to assess paracetamol levels, liver function, and other parameters. Referral to a medical or liver unit may be necessary, and psychiatric follow-up should be considered for deliberate overdoses.
In cases of staggered ingestion, all patients should be treated with NAC without delay. Blood tests are also taken, and if certain criteria are met, NAC can be discontinued. Adverse reactions to NAC are common and may include anaphylactoid reactions, rash, hypotension, and nausea. Treatment for adverse reactions involves medications such as chlorpheniramine and salbutamol, and the infusion may be stopped if necessary.
The prognosis for paracetamol poisoning can be poor, especially in cases of severe liver injury. Fulminant liver failure may occur, and liver transplant may be necessary. Poor prognostic indicators include low arterial pH, prolonged prothrombin time, high plasma creatinine, and hepatic encephalopathy.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 43
Incorrect
-
A 68 year old patient with dementia is brought into the emergency department by a caregiver due to a suspected accidental overdose. The caregiver reports finding several of the patient's medication bottles with multiple tablets missing. An ECG is conducted and reveals a prolonged QT interval. The caregiver presents you with the medication containers. Which of the following medications is the most probable culprit for the prolonged QT interval?
Your Answer:
Correct Answer: Citalopram
Explanation:Antipsychotics and antidepressants are drugs that are known to cause QT prolongation, which is a potentially dangerous heart rhythm abnormality. Similarly, SSRIs and other antidepressants are also associated with QT prolongation. On the other hand, beta-blockers like bisoprolol are used to shorten the QT interval and are considered as a treatment option for long QT syndrome. However, it’s important to note that sotalol, although classified as a beta blocker, acts differently by blocking potassium channels. This unique mechanism of action makes sotalol a class III anti-arrhythmic agent and may result in QT interval prolongation.
Further Reading:
Long QT syndrome (LQTS) is a condition characterized by a prolonged QT interval on an electrocardiogram (ECG), which represents abnormal repolarization of the heart. LQTS can be either acquired or congenital. Congenital LQTS is typically caused by gene abnormalities that affect ion channels responsible for potassium or sodium flow in the heart. There are 15 identified genes associated with congenital LQTS, with three genes accounting for the majority of cases. Acquired LQTS can be caused by various factors such as certain medications, electrolyte imbalances, hypothermia, hypothyroidism, and bradycardia from other causes.
The normal QTc values, which represent the corrected QT interval for heart rate, are typically less than 450 ms for men and less than 460ms for women. Prolonged QTc intervals are considered to be greater than these values. It is important to be aware of drugs that can cause QT prolongation, as this can lead to potentially fatal arrhythmias. Some commonly used drugs that can cause QT prolongation include antimicrobials, antiarrhythmics, antipsychotics, antidepressants, antiemetics, and others.
Management of long QT syndrome involves addressing any underlying causes and using beta blockers. In some cases, an implantable cardiac defibrillator (ICD) may be recommended for patients who have experienced recurrent arrhythmic syncope, documented torsades de pointes, previous ventricular tachyarrhythmias or torsades de pointes, previous cardiac arrest, or persistent syncope. Permanent pacing may be used in patients with bradycardia or atrioventricular nodal block and prolonged QT. Mexiletine is a treatment option for those with LQT3. Cervicothoracic sympathetic denervation may be considered in patients with recurrent syncope despite beta-blockade or in those who are not ideal candidates for an ICD. The specific treatment options for LQTS depend on the type and severity of the condition.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 44
Incorrect
-
You are overseeing the care of a patient who has received intravenous lipid emulsion. As the patient recovers over the next hour, it is important to continue monitoring for which side effect of this medication?
Your Answer:
Correct Answer: Pancreatitis
Explanation:Lipid emulsion is known to cause pancreatitis as a common side effect. According to the AAGBI guidelines, patients who are given lipid emulsion should be closely monitored with regular clinical evaluations. This includes conducting amylase or lipase tests daily for two days after receiving the emulsion.
Further Reading:
Local anaesthetics, such as lidocaine, bupivacaine, and prilocaine, are commonly used in the emergency department for topical or local infiltration to establish a field block. Lidocaine is often the first choice for field block prior to central line insertion. These anaesthetics work by blocking sodium channels, preventing the propagation of action potentials.
However, local anaesthetics can enter the systemic circulation and cause toxic side effects if administered in high doses. Clinicians must be aware of the signs and symptoms of local anaesthetic systemic toxicity (LAST) and know how to respond. Early signs of LAST include numbness around the mouth or tongue, metallic taste, dizziness, visual and auditory disturbances, disorientation, and drowsiness. If not addressed, LAST can progress to more severe symptoms such as seizures, coma, respiratory depression, and cardiovascular dysfunction.
The management of LAST is largely supportive. Immediate steps include stopping the administration of local anaesthetic, calling for help, providing 100% oxygen and securing the airway, establishing IV access, and controlling seizures with benzodiazepines or other medications. Cardiovascular status should be continuously assessed, and conventional therapies may be used to treat hypotension or arrhythmias. Intravenous lipid emulsion (intralipid) may also be considered as a treatment option.
If the patient goes into cardiac arrest, CPR should be initiated following ALS arrest algorithms, but lidocaine should not be used as an anti-arrhythmic therapy. Prolonged resuscitation may be necessary, and intravenous lipid emulsion should be administered. After the acute episode, the patient should be transferred to a clinical area with appropriate equipment and staff for further monitoring and care.
It is important to report cases of local anaesthetic toxicity to the appropriate authorities, such as the National Patient Safety Agency in the UK or the Irish Medicines Board in the Republic of Ireland. Additionally, regular clinical review should be conducted to exclude pancreatitis, as intravenous lipid emulsion can interfere with amylase or lipase assays.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 45
Incorrect
-
A 35-year-old woman with a history of epilepsy presents with a complaint of gum swelling. Upon examination, significant gum hypertrophy is noted.
Which SPECIFIC anti-epileptic medication is she most likely to be prescribed?Your Answer:
Correct Answer: Phenytoin
Explanation:Phenytoin is widely known for its ability to cause gum hypertrophy. This condition is believed to occur as a result of decreased folate levels, but studies have shown that taking folic acid supplements can help prevent it. In addition to gum hypertrophy, other side effects that may occur with phenytoin use include megaloblastic anemia, nystagmus, ataxia, hypertrichosis, pruritic rash, hirsutism, and drug-induced lupus.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 46
Incorrect
-
A child presents with a severe acute asthma attack. After a poor response to the initial salbutamol nebulizer, you administer another nebulizer that also contains ipratropium bromide.
What is the most common side effect experienced with ipratropium bromide?Your Answer:
Correct Answer: Dry mouth
Explanation:Ipratropium bromide commonly leads to dry mouth as a side effect. Additionally, it may result in constipation, cough, sudden bronchospasm, headache, nausea, and palpitations. In patients with prostatic hyperplasia and bladder outflow obstruction, it can cause urinary retention. Furthermore, susceptible individuals may experience acute closed-angle glaucoma as a result of using this medication.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 47
Incorrect
-
You evaluate a 72-year-old woman who has recently been prescribed amiodarone.
Which ONE statement about the adverse effects of amiodarone is accurate?Your Answer:
Correct Answer: It can cause jaundice
Explanation:Amiodarone is a medication that can have numerous harmful side effects, making it crucial to conduct a comprehensive clinical assessment before starting treatment with it. Some of the side effects associated with amiodarone include corneal microdeposits, photosensitivity, nausea, sleep disturbance, hyperthyroidism, hypothyroidism, acute hepatitis and jaundice, peripheral neuropathy, lung fibrosis, QT prolongation, and optic neuritis (although this is very rare). If optic neuritis occurs, immediate discontinuation of amiodarone is necessary to prevent the risk of blindness.
The majority of patients taking amiodarone experience corneal microdeposits, but these typically resolve after treatment is stopped and rarely affect vision. Amiodarone has a chemical structure similar to thyroxine and can bind to the nuclear thyroid receptor, leading to both hypothyroidism and hyperthyroidism. However, hypothyroidism is more commonly observed, affecting around 5-10% of patients.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 48
Incorrect
-
A 67 year old individual experiences muscle rigidity and fever after being intubated. Your supervisor instructs you to administer dantrolene. What is the mechanism of action of dantrolene?
Your Answer:
Correct Answer: Inhibits calcium efflux from the sarcoplasmic reticulum
Explanation:Dantrolene works by blocking the release of calcium ions from the sarcoplasmic reticulum in skeletal muscle cells. This reduces the amount of calcium available to bind to troponin on actin filaments, which in turn decreases the muscle’s ability to contract and reduces energy usage.
Further Reading:
Malignant hyperthermia is a rare and life-threatening syndrome that can be triggered by certain medications in individuals who are genetically susceptible. The most common triggers are suxamethonium and inhalational anaesthetic agents. The syndrome is caused by the release of stored calcium ions from skeletal muscle cells, leading to uncontrolled muscle contraction and excessive heat production. This results in symptoms such as high fever, sweating, flushed skin, rapid heartbeat, and muscle rigidity. It can also lead to complications such as acute kidney injury, rhabdomyolysis, and metabolic acidosis. Treatment involves discontinuing the trigger medication, administering dantrolene to inhibit calcium release and promote muscle relaxation, and managing any associated complications such as hyperkalemia and acidosis. Referral to a malignant hyperthermia center for further investigation is also recommended.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 49
Incorrect
-
A 32-year-old woman is admitted to the department after ingesting an excessive amount of tricyclic antidepressants (TCAs) four hours ago.
Which of the following ECG findings is most frequently observed in cases of TCA overdose?Your Answer:
Correct Answer: Sinus tachycardia
Explanation:The most commonly observed change in the electrocardiogram (ECG) during a tricyclic antidepressant (TCA) overdose is sinus tachycardia. Additionally, other ECG changes that can be seen in TCA overdose include prolongation of the PR interval, broadening of the QRS complex, prolongation of the QT interval, and the occurrence of ventricular arrhythmias in cases of severe toxicity. The cardiotoxic effects of TCAs are caused by the blocking of sodium channels, which leads to broadening of the QRS complex, and the blocking of potassium channels, which results in prolongation of the QT interval. The severity of the QRS broadening is associated with adverse events: a QRS duration greater than 100 ms is predictive of seizures, while a QRS duration greater than 160 ms is predictive of ventricular arrhythmias.
-
This question is part of the following fields:
- Pharmacology & Poisoning
-
-
Question 50
Incorrect
-
A 40-year-old man is brought to the Emergency Department by his wife after taking an overdose of one of his prescribed medications. He is agitated, confused, and experiencing visual hallucinations. His heart rate is currently 115 bpm, and his pupils are dilated. Obtaining a history from him is challenging as he is mumbling. Further questioning reveals that he has ingested an anticholinergic drug.
What is the most suitable initial treatment for this patient?Your Answer:
Correct Answer: Diazepam
Explanation:Patients who present with an anticholinergic toxidrome can be difficult to manage due to the agitation and disruptive behavior that is typically present. It is important to provide meticulous supportive care to address the behavioral effects of delirium and prevent complications such as dehydration, injury, and pulmonary aspiration. Often, one-to-one nursing is necessary.
The management approach for these patients is as follows:
1. Resuscitate using a standard ABC approach.
2. Administer sedation for behavioral control. Benzodiazepines, such as IV diazepam in 5 mg-10 mg increments, are the first-line therapy. The goal is to achieve a patient who is sleepy but easily roused. It is important to avoid over-sedating the patient as this can increase the risk of aspiration.
3. Prescribe intravenous fluids as patients are typically unable to eat and drink, and may be dehydrated upon presentation.
4. Insert a urinary catheter as urinary retention is often present and needs to be managed.
5. Consider physostigmine as the specific antidote for anticholinergic delirium in carefully selected cases. Physostigmine acts as a reversible acetylcholinesterase inhibitor, temporarily blocking the breakdown of acetylcholine. This enhances its effects at muscarinic and nicotinic receptors, thereby reversing the effects of the anticholinergic agents.Physostigmine is indicated in the following situations:
1. Severe anticholinergic delirium that does not respond to benzodiazepine sedation.
2. Poisoning with a pure anticholinergic agent, such as atropine.The dosage and administration of physostigmine are as follows:
1. Administer in a monitored setting with appropriate staff and resources to manage adverse effects.
2. Perform a 12-lead ECG before administration to rule out bradycardia, AV block, or broadening of the QRS.
3. Administer IV physostigmine 0.5-1 mg as a slow push over 5 minutes. Repeat every 10 minutes up to a maximum of 4 mg.
4. The clinical end-point of therapy is the resolution of delirium.
5. Delirium may reoccur in 1-4 hours as the effects of physostigmine wear off. In such cases, the dose may be cautiously repeated. -
This question is part of the following fields:
- Pharmacology & Poisoning
-
00
Correct
00
Incorrect
00
:
00
:
00
Session Time
00
:
00
Average Question Time (
Mins)