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Question 1
Correct
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Which one of the following statements regarding metformin is true?
Your Answer: Should be stopped in a patient admitted with a myocardial infarction
Explanation:After a heart attack, Metformin usage should be discontinued as it can increase the risk of lactic acidosis. However, it can be reintroduced at a later time. To manage diabetes, an insulin/dextrose infusion such as the DIGAMI regimen can be used.
Metformin is a medication commonly used to treat type 2 diabetes mellitus. It belongs to a class of drugs called biguanides and works by activating the AMP-activated protein kinase (AMPK), which increases insulin sensitivity and reduces hepatic gluconeogenesis. Additionally, it may decrease the absorption of carbohydrates in the gastrointestinal tract. Unlike other diabetes medications, such as sulphonylureas, metformin does not cause hypoglycemia or weight gain, making it a first-line treatment option, especially for overweight patients. It is also used to treat polycystic ovarian syndrome and non-alcoholic fatty liver disease.
While metformin is generally well-tolerated, gastrointestinal side effects such as nausea, anorexia, and diarrhea are common and can be intolerable for some patients. Reduced absorption of vitamin B12 is also a potential side effect, although it rarely causes clinical problems. In rare cases, metformin can cause lactic acidosis, particularly in patients with severe liver disease or renal failure. However, it is important to note that lactic acidosis is now recognized as a rare side effect of metformin.
There are several contraindications to using metformin, including chronic kidney disease, recent myocardial infarction, sepsis, acute kidney injury, severe dehydration, and alcohol abuse. Additionally, metformin should be discontinued before and after procedures involving iodine-containing x-ray contrast media to reduce the risk of contrast nephropathy.
When starting metformin, it is important to titrate the dose slowly to reduce the incidence of gastrointestinal side effects. If patients experience intolerable side effects, modified-release metformin may be considered as an alternative.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 2
Correct
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Which of the following medications is most likely to cause a rash when exposed to sunlight?
Your Answer: Tetracycline
Explanation:Drugs that can cause sensitivity to light
Photosensitivity is a condition where the skin becomes more sensitive to light, resulting in rashes, blisters, and other skin irritations. Certain drugs can cause photosensitivity, making it important to be aware of the medications that can cause this condition. Some of the drugs that can cause photosensitivity include thiazides, tetracyclines, sulphonamides, ciprofloxacin, amiodarone, NSAIDs like piroxicam, psoralens, and sulphonylureas.
Thiazides are a type of diuretic that can cause photosensitivity, while tetracyclines, sulphonamides, and ciprofloxacin are antibiotics that can also cause this condition. Amiodarone is a medication used to treat heart rhythm problems, but it can also cause photosensitivity. NSAIDs like piroxicam are pain relievers that can cause photosensitivity, while psoralens are used to treat skin conditions like psoriasis and can also cause photosensitivity. Sulphonylureas are medications used to treat diabetes that can cause photosensitivity as well.
It is important to note that not everyone who takes these medications will experience photosensitivity, but it is still important to be aware of the potential side effects.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 3
Correct
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A 32-year-old patient who is 30 weeks' pregnant with her first baby is urgently referred by her GP to the Obstetric/Endocrine Joint Clinic with newly diagnosed symptomatic hyperthyroidism.
Which of the following statements is true concerning the management of maternal thyrotoxicosis in pregnancy with carbimazole or propylthiouracil?Your Answer: Propylthiouracil crosses the placenta
Explanation:Thyroid Management During Pregnancy: Considerations and Recommendations
Pregnancy can have a significant impact on thyroid function, and thyroid dysfunction can occur in many pregnant women due to pathological processes. Anti-thyroid drugs such as propylthiouracil and carbimazole can cross the placenta, potentially causing fetal goitre and hypothyroidism. It is recommended to keep the dose of these drugs as low as possible to maintain euthyroidism during pregnancy. Neonatal goitre and hypothyroidism can occur even with low-dose anti-thyroid drugs, and the neonatal goitre is permanent if it occurs.
Block-and-replace therapy with carbimazole and thyroxine is appropriate maternal management only in the treatment of isolated fetal hyperthyroidism caused by maternal TSH receptor antibody production in a mother who previously received ablative therapy for Graves’ disease. The neonatal goitre and hypothyroidism normalise in a few days’ time, and the confirmatory tests will come back normal even if the TSH is high on screening.
Specialist assessment is needed to differentiate between Graves’ hyperthyroidism and gestational hyperthyroidism. Women treated with anti-thyroid drugs may need to have the drug or dose amended by a specialist at the diagnosis of pregnancy, because these drugs cross the placenta. Women with current or previous Graves’ disease should have their TSH receptor antibody levels measured by the specialist. Carbimazole and propylthiouracil are present in breast milk, but this does not preclude breastfeeding as long as neonatal development is closely monitored and the lowest effective dose is used.
In summary, thyroid management during pregnancy requires careful consideration and monitoring to ensure the health of both the mother and the fetus.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 4
Correct
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A 38-year-old woman with rheumatoid arthritis visits her doctor every three months for blood tests. Which of the following blood tests is necessary for monitoring the use of methotrexate?
Your Answer: FBC, U&Es, LFTs
Explanation:Importance of Drug Monitoring in Primary Care
Patients on methotrexate require regular monitoring of their blood tests to prevent severe side effects. The three essential blood tests that need monitoring are FBC, U&Es, and LFTs. Methotrexate can cause blood dyscrasias, liver cirrhosis, and kidney failure, making it crucial to monitor these tests every 2-3 months once therapy has stabilized. Patients should report any symptoms of infection, bruising, mouth ulcers, abdominal discomfort, dark urine, and shortness of breath. They should also avoid self-medication with over-the-counter aspirin or ibuprofen.
Thyroid function is not affected by methotrexate, and regular monitoring is not necessary unless there is another medical condition that justifies it. However, patients on methotrexate should report any signs of blood disorders such as ecchymosis and telangiectasia.
Drug monitoring is becoming increasingly common in primary care, especially for patients under shared care with secondary/specialty care. Some examples of drug monitoring in primary care include amiodarone, azathioprine, lithium, and methotrexate. Each drug requires specific blood tests, and the frequency of monitoring varies. For instance, patients on methotrexate require FBC, U&Es, and LFTs every 2-3 months.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 5
Correct
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You are working in a busy emergency department. A 25-year-old male presents explaining that a few hours ago he broke up with his girlfriend and while having an argument took 20 of his mother's tablets. He is worried and says he is experiencing muffled hearing with bouts of ringing on both sides. Vital signs were all normal apart from a respiratory rate of 28 per minute.
An overdose of which medication is most likely?Your Answer: Aspirin
Explanation:Tinnitus could be an early indication of an aspirin overdose, as salicylate toxicity can cause respiratory alkalosis and subsequently metabolic acidosis within a few hours. The patient’s symptoms suggest the former, and the presence of tinnitus further supports this diagnosis.
Salicylate overdose can result in a combination of respiratory alkalosis and metabolic acidosis. The initial effect of salicylates is to stimulate the respiratory center, leading to hyperventilation and respiratory alkalosis. However, as the overdose progresses, the direct acid effects of salicylates, combined with acute renal failure, can cause metabolic acidosis. In children, metabolic acidosis tends to be more prominent. Other symptoms of salicylate overdose include tinnitus, lethargy, sweating, pyrexia, nausea/vomiting, hyperglycemia and hypoglycemia, seizures, and coma.
The treatment for salicylate overdose involves general measures such as airway, breathing, and circulation support, as well as administering activated charcoal. Urinary alkalinization with intravenous sodium bicarbonate can help eliminate aspirin in the urine. In severe cases, hemodialysis may be necessary. Indications for hemodialysis include a serum concentration of salicylates greater than 700mg/L, metabolic acidosis that is resistant to treatment, acute renal failure, pulmonary edema, seizures, and coma.
It is important to note that salicylates can cause the uncoupling of oxidative phosphorylation, which leads to decreased adenosine triphosphate production, increased oxygen consumption, and increased carbon dioxide and heat production. Therefore, prompt and appropriate treatment is crucial in managing salicylate overdose.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 6
Correct
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A 30-year-old man with a known history of peanut allergy arrives at the Emergency Department with facial swelling. Upon examination, his blood pressure is 85/60 mmHg, pulse is 120 bpm, and he has a bilateral expiratory wheeze. Which type of adrenaline should be administered?
Your Answer: 0.5ml 1:1,000 IM
Explanation:Please find below the recommended doses of adrenaline for Adult Life Support (ALS) in different scenarios:
– Anaphylaxis: 0.5mg or 0.5ml of 1:1,000 adrenaline should be administered intramuscularly.
– Cardiac arrest: For intravenous administration, 1mg or 10ml of 1:10,000 adrenaline or 1ml of 1:1000 adrenaline is recommended.Understanding Adrenaline and Its Indications
Adrenaline is a type of sympathomimetic amine that has both alpha and beta adrenergic stimulating properties. It is commonly used in emergency situations such as anaphylaxis and cardiac arrest. For anaphylaxis, the recommended adult life support adrenaline dose is 0.5ml 1:1,000 IM, while for cardiac arrest, it is 10ml 1:10,000 IV or 1ml of 1:1000 IV.
Adrenaline is responsible for the fight or flight response and is released by the adrenal glands. It acts on α 1 and 2, β 1 and 2 receptors, and causes vasoconstriction in the skin and kidneys, resulting in a narrow pulse pressure. It also increases cardiac output and total peripheral resistance, while causing vasodilation in skeletal muscle vessels.
When adrenaline acts on α adrenergic receptors, it inhibits insulin secretion by the pancreas and stimulates glycogenolysis in the liver and muscle. On the other hand, when it acts on β adrenergic receptors, it stimulates glucagon secretion in the pancreas, stimulates ACTH, and stimulates lipolysis by adipose tissue.
In case of accidental injection, the management involves local infiltration of phentolamine. Understanding the indications and actions of adrenaline is crucial in emergency situations, and proper administration can help save lives.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 7
Correct
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A 28-year-old female with no significant medical history is started on carbamazepine for focal impaired awareness seizures. She drinks alcohol moderately. After three months, she experiences a series of seizures and her carbamazepine levels are found to be subtherapeutic. Despite being fully compliant, a pill-count reveals this. What is the probable cause?
Your Answer: Auto-induction of liver enzymes
Explanation:Carbamazepine induces the P450 enzyme system, leading to increased metabolism of carbamazepine through auto-induction.
P450 Enzyme System and its Inducers and Inhibitors
The P450 enzyme system is responsible for metabolizing drugs in the body. Induction of this system usually requires prolonged exposure to the inducing drug, unlike P450 inhibitors, which have rapid effects. Some drugs that induce the P450 system include antiepileptics like phenytoin and carbamazepine, barbiturates such as phenobarbitone, rifampicin, St John’s Wort, chronic alcohol intake, griseofulvin, and smoking, which affects CYP1A2 and is the reason why smokers require more aminophylline.
On the other hand, some drugs inhibit the P450 system, including antibiotics like ciprofloxacin and erythromycin, isoniazid, cimetidine, omeprazole, amiodarone, allopurinol, imidazoles such as ketoconazole and fluconazole, SSRIs like fluoxetine and sertraline, ritonavir, sodium valproate, and acute alcohol intake. It is important to be aware of these inducers and inhibitors as they can affect the metabolism and efficacy of drugs in the body. Proper dosing and monitoring can help ensure safe and effective treatment.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 8
Correct
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A 63-year-old man visits your clinic for his regular asthma inhaler prescription. During the consultation, he mentions experiencing difficulty in sustaining his erections and requests a prescription for sildenafil. What is the most prevalent side effect of sildenafil?
Your Answer: Headaches
Explanation:Sildenafil is frequently prescribed in primary care. Adverse effects of sildenafil consist of headaches, facial flushing, indigestion, and temporary visual disturbances with a blue-green tint.
Understanding Phosphodiesterase Type V Inhibitors
Phosphodiesterase type V (PDE5) inhibitors are medications used to treat erectile dysfunction and pulmonary hypertension. These drugs work by increasing the levels of cGMP, which leads to the relaxation of smooth muscles in the blood vessels supplying the corpus cavernosum. The most well-known PDE5 inhibitor is sildenafil, also known as Viagra, which was the first drug of its kind. It is a short-acting medication that is usually taken one hour before sexual activity.
Other PDE5 inhibitors include tadalafil (Cialis) and vardenafil (Levitra). Tadalafil is longer-acting than sildenafil and can be taken on a regular basis, while vardenafil has a similar duration of action to sildenafil. However, these drugs are not suitable for everyone. Patients taking nitrates or related drugs, those with hypotension, and those who have had a recent stroke or myocardial infarction should not take PDE5 inhibitors.
Like all medications, PDE5 inhibitors can cause side effects. These may include visual disturbances, blue discolouration, non-arteritic anterior ischaemic neuropathy, nasal congestion, flushing, gastrointestinal side-effects, headache, and priapism. It is important to speak to a healthcare professional before taking any medication to ensure that it is safe and appropriate for you.
Overall, PDE5 inhibitors are an effective treatment for erectile dysfunction and pulmonary hypertension. However, they should only be used under the guidance of a healthcare professional and with careful consideration of the potential risks and benefits.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 9
Correct
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As a foundation doctor on the neonatal ward, you are updating a prescription chart for a premature baby born at twenty-six weeks. While reviewing the chart, you come across sildenafil. Can you explain the purpose of sildenafil in neonatal care?
Your Answer: Treating pulmonary hypertension
Explanation:Sildenafil, also known as Viagra, is typically used to treat erectile dysfunction in adults. However, it can also be used to treat pulmonary hypertension in neonates. The appropriate method for calming a distressed neonate depends on the underlying cause, which is often related to respiratory distress or pain. Gaviscon and ranitidine are sometimes used to treat gastro-oesophageal reflux, although this is not an approved use. Caffeine is sometimes used to help wean a neonate off a ventilator.
Understanding Phosphodiesterase Type V Inhibitors
Phosphodiesterase type V (PDE5) inhibitors are medications used to treat erectile dysfunction and pulmonary hypertension. These drugs work by increasing the levels of cGMP, which leads to the relaxation of smooth muscles in the blood vessels supplying the corpus cavernosum. The most well-known PDE5 inhibitor is sildenafil, also known as Viagra, which was the first drug of its kind. It is a short-acting medication that is usually taken one hour before sexual activity.
Other PDE5 inhibitors include tadalafil (Cialis) and vardenafil (Levitra). Tadalafil is longer-acting than sildenafil and can be taken on a regular basis, while vardenafil has a similar duration of action to sildenafil. However, these drugs are not suitable for everyone. Patients taking nitrates or related drugs, those with hypotension, and those who have had a recent stroke or myocardial infarction should not take PDE5 inhibitors.
Like all medications, PDE5 inhibitors can cause side effects. These may include visual disturbances, blue discolouration, non-arteritic anterior ischaemic neuropathy, nasal congestion, flushing, gastrointestinal side-effects, headache, and priapism. It is important to speak to a healthcare professional before taking any medication to ensure that it is safe and appropriate for you.
Overall, PDE5 inhibitors are an effective treatment for erectile dysfunction and pulmonary hypertension. However, they should only be used under the guidance of a healthcare professional and with careful consideration of the potential risks and benefits.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 10
Correct
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An 80-year-old man comes in for a routine check-up with his General Practitioner. He has a medical history of atrial fibrillation, type II diabetes, depression, and chronic alcohol abuse. His current medications include warfarin 3 mg once daily, ramipril 2.5 mg once daily, bisoprolol 2 mg once daily, erythromycin 500 mg four times daily (day five of a 7-day course for cellulitis on the leg), and sertraline 50 mg once daily (started four weeks ago). He is allergic to penicillin. His blood work shows an INR of 6.5 (target 2.0-3.0). What is the most likely reason for his elevated INR?
Your Answer: Erythromycin is a P450 inhibiter
Explanation:The patient is taking erythromycin for cellulitis, which inhibits the cytochrome P450 enzymes responsible for breaking down drugs like warfarin and statins. As a result, the effects of warfarin are potentiated, leading to a higher than expected INR. Bisoprolol is unlikely to have contributed to the change in INR as it does not affect the P450 system. Chronic alcohol abuse can induce P450 enzymes, but this would cause a lower INR. Erythromycin is an inhibitor, not an inducer, of P450 enzymes. Sertraline, though recently started, is also an enzyme inhibitor and cannot explain the high INR.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 11
Correct
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A 35-year-old man presents with a 5-month history of cough, fever, and unexplained weight loss. Acid-fast bacilli are detected in his sputum culture. He is prescribed a drug regimen consisting of isoniazid and rifampicin for 6 months, along with ethambutol and pyrazinamide for the first 2 months. Additionally, he is advised to take pyridoxine to prevent which complication?
Your Answer: Peripheral neuropathy
Explanation:Prescribing pyridoxine can help lower the risk of peripheral neuropathy associated with isoniazid.
Side-Effects and Mechanism of Action of Tuberculosis Drugs
Rifampicin is a drug that inhibits bacterial DNA dependent RNA polymerase, which prevents the transcription of DNA into mRNA. However, it is a potent liver enzyme inducer and can cause hepatitis, orange secretions, and flu-like symptoms.
Isoniazid, on the other hand, inhibits mycolic acid synthesis. It can cause peripheral neuropathy, which can be prevented with pyridoxine (Vitamin B6). It can also cause hepatitis and agranulocytosis. Additionally, it is a liver enzyme inhibitor.
Pyrazinamide is converted by pyrazinamidase into pyrazinoic acid, which in turn inhibits fatty acid synthase (FAS) I. However, it can cause hyperuricaemia, leading to gout, as well as arthralgia, myalgia, and hepatitis.
Lastly, Ethambutol inhibits the enzyme arabinosyl transferase, which polymerizes arabinose into arabinan. It can cause optic neuritis, so it is important to check visual acuity before and during treatment. Additionally, the dose needs adjusting in patients with renal impairment.
In summary, these tuberculosis drugs have different mechanisms of action and can cause various side-effects. It is important to monitor patients closely and adjust treatment accordingly to ensure the best possible outcomes.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 12
Incorrect
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A 65-year-old man visits his GP for a medication review. He has been diagnosed with stable congestive heart failure. As you review his repeat prescriptions, you consider his new diagnosis. The patient has type 2 diabetes mellitus, osteoarthritis, and erectile dysfunction. What is the most crucial medication to avoid in patients with chronic heart failure among his current medications?
Your Answer: Metformin
Correct Answer: Diclofenac
Explanation:Patients with heart failure should exercise caution when using NSAIDs as they have the potential to worsen the condition by causing fluid retention, particularly diclofenac.
Medications to Avoid in Patients with Heart Failure
Heart failure is a serious condition that requires careful management of medications. Some medications can exacerbate heart failure and should be avoided. Thiazolidinediones, such as pioglitazone, are contraindicated as they cause fluid retention. Verapamil has a negative inotropic effect and should be used with caution. NSAIDs and glucocorticoids can also cause fluid retention and should be used with caution. However, low-dose aspirin is an exception as many patients with heart failure also have coexistent cardiovascular disease and the benefits of taking aspirin easily outweigh the risks. Class I antiarrhythmics, such as flecainide, have a negative inotropic and proarrhythmic effect and should be avoided. It is important for healthcare providers to be aware of these medications and to carefully consider their use in patients with heart failure.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 13
Correct
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A 72-year-old male presents to the surgical assessment unit with lower abdominal pain and inability to pass urine for the past 12 hours. He has a palpable bladder and tenderness in the suprapubic region. On PR examination, his prostate is smooth and not enlarged. He has a medical history of high blood pressure, depression, neuropathic pain, and diabetes. What could be the probable cause of his presentation?
Your Answer: Amitriptyline
Explanation:Urinary retention can be caused by Amitriptyline due to its anticholinergic activity. The patient, who has a small prostate on PR examination, is currently experiencing urinary retention. None of the other medications are known to cause this condition.
Drugs that can cause urinary retention
Urinary retention is a condition where a person is unable to empty their bladder completely. This can be caused by various factors, including certain medications. Some drugs that may lead to urinary retention include tricyclic antidepressants like amitriptyline, anticholinergics such as antipsychotics and antihistamines, opioids, NSAIDs, and disopyramide. These drugs can affect the muscles that control the bladder, making it difficult to urinate.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 14
Incorrect
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A 38-year-old man visits his General Practitioner complaining of a sore throat. He has a Centor score of 4 due to the presence of a fever, cervical lymphadenopathy, absence of cough, and white exudate on his tonsils. He is allergic to penicillin and takes simvastatin as his only medication. What is the most suitable antibiotic to prescribe for his sore throat?
Your Answer: Erythromycin
Correct Answer: Doxycycline
Explanation:A patient with a Centor score of 4 likely has acute group A streptococcal tonsillitis and requires antibiotics. However, the patient is allergic to penicillins and takes simvastatin, which is metabolized by the cytochrome P450 enzymes. Phenoxymethylpenicillin, the usual first-line treatment, cannot be used due to the allergy. Macrolides such as clarithromycin and erythromycin should also be avoided as they inhibit the cytochrome P450 enzymes and can increase the risk of statin-induced myopathy. Co-amoxiclav is not an option either. Therefore, doxycycline is the best choice as it is not a penicillin and does not affect the cytochrome P450 enzymes, allowing for concurrent use with simvastatin.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 15
Incorrect
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A 25-year-old man presents to the emergency department after experiencing syncope. He reports an increase in palpitations since starting a new medication. On examination, his ECG reveals a prolonged QT interval of 500 msec. What is the probable medication he is taking?
Your Answer: Lymecycline
Correct Answer: Citalopram
Explanation:Prolonged QT interval syndrome can be caused by tricyclic antidepressants and selective serotonin reuptake inhibitors, with citalopram being particularly associated with this effect. As a result, the MHRA issued a warning on its use and reduced the maximum recommended daily dose from 80 mg to 40mg due to the dose-dependent nature of QT prolongation. Although not mandatory, some GPs may request an initial ECG before prescribing citalopram.
Understanding Long QT Syndrome
Long QT syndrome (LQTS) is a genetic condition that causes delayed repolarization of the ventricles, which can lead to ventricular tachycardia and sudden death. The most common types of LQTS are caused by defects in the alpha subunit of the slow delayed rectifier potassium channel. A normal corrected QT interval is less than 430 ms in males and 450 ms in females.
There are various causes of a prolonged QT interval, including congenital factors, drugs, and other medical conditions. Some drugs that can prolong the QT interval include amiodarone, tricyclic antidepressants, and selective serotonin reuptake inhibitors. Electrolyte imbalances, acute myocardial infarction, and subarachnoid hemorrhage can also cause a prolonged QT interval.
LQTS may be picked up on routine ECG or following family screening. The symptoms and events associated with LQTS can vary depending on the type of LQTS. Long QT1 is usually associated with exertional syncope, while Long QT2 is often associated with syncope following emotional stress or exercise. Long QT3 events often occur at night or at rest.
Management of LQTS involves avoiding drugs that prolong the QT interval and other precipitants if appropriate. Beta-blockers may be used, and in high-risk cases, implantable cardioverter defibrillators may be necessary. It is important to recognize and manage LQTS to prevent sudden cardiac death.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 16
Correct
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A 32-year-old woman with epilepsy complains of acne and bleeding gums. Which medication is most likely responsible for these symptoms?
Your Answer: Phenytoin
Explanation:Side Effects of Common Anticonvulsants
Anticonvulsants are medications used to treat seizures and epilepsy. However, they commonly have side effects that patients should be aware of. Here are some of the common or more serious side effects reported for some of the most commonly prescribed anticonvulsants:
Phenytoin: This medication can cause paraesthesia, gingival hypertrophy, tiredness, acne, hirsutism, coarsening of facial appearance, peripheral neuropathy, Steven-Johnson syndrome, and blood dyscrasias (such as aplastic anaemia and megaloblastic anaemia).
Sodium valproate (Epilim®): Side effects of this medication may include weight gain, thrombocytopenia, transient hair loss, aggression and behavioural changes, ataxia and tremors.
Carbamazepine: Dry mouth, fatigue, hyponatraemia, blood dyscrasia (such as aplastic anaemia), thrombocytopenia, haemolytic anaemia, eosinophilia, dermatitis, gynaecomastia, male infertility, hepatitis, and restlessness are all possible side effects of this medication.
Lamotrigine (Lamictal®): Skin rash and hypersensitivity, blurred vision, dizziness, sleep disturbance, and joint pains are some of the side effects that may occur with this medication.
Levetiracetam (Keppra®): Weight change and anorexia, abdominal pains, nausea, diarrhoea, and anxiety are all possible side effects of this medication.
It’s important to note that gingival hypertrophy and tenderness are common effects of phenytoin, but not the other medications listed. Patients taking phenytoin should be encouraged to maintain good oral hygiene. Overall, patients should be aware of the potential side effects of their anticonvulsant medication and discuss any concerns with their healthcare provider.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 17
Correct
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A 68-year-old male patient presents to discuss his recent blood test results. He has been taking ramipril for 6 weeks and his blood pressure has been well controlled. His baseline creatinine level was 92 µmol/L. However, his most recent creatinine level has increased to 118 µmol/L and he is concerned about the potential impact on his kidney function.
What would be the most suitable course of action in this situation?Your Answer: Continue current dose of ramipril and check urea and electrolytes at 3 months
Explanation:Angiotensin-converting enzyme (ACE) inhibitors are commonly used as the first-line treatment for hypertension and heart failure in younger patients. However, they may not be as effective in treating hypertensive Afro-Caribbean patients. These inhibitors are also used to treat diabetic nephropathy and for secondary prevention of ischaemic heart disease. The mechanism of action of ACE inhibitors is to inhibit the conversion of angiotensin I to angiotensin II. They are metabolized in the liver through phase 1 metabolism.
ACE inhibitors may cause side effects such as cough, which occurs in around 15% of patients and may occur up to a year after starting treatment. This is thought to be due to increased bradykinin levels. Angioedema may also occur up to a year after starting treatment. Hyperkalaemia and first-dose hypotension are other potential side effects, especially in patients taking diuretics. ACE inhibitors should be avoided during pregnancy and breastfeeding, and caution should be exercised in patients with renovascular disease, aortic stenosis, or hereditary or idiopathic angioedema.
Patients receiving high-dose diuretic therapy (more than 80 mg of furosemide a day) are at an increased risk of hypotension when taking ACE inhibitors. Before initiating treatment, urea and electrolytes should be checked, and after increasing the dose, a rise in creatinine and potassium may be expected. Acceptable changes include an increase in serum creatinine up to 30% from baseline and an increase in potassium up to 5.5 mmol/l. Patients with undiagnosed bilateral renal artery stenosis may experience significant renal impairment. The current NICE guidelines provide a flow chart for the management of hypertension.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 18
Correct
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You are reviewing an elderly patient with difficult-to-treat angina and consider that a trial of treatment with nicorandil may be appropriate.
Which of the following statements is true about the anti-anginal drug nicorandil?
Your Answer: Oral ulceration is an unwanted effect
Explanation:Understanding the Effects and Side Effects of Nicorandil
Nicorandil is a medication that is commonly used to treat angina pectoris, a condition characterized by chest pain or discomfort caused by reduced blood flow to the heart. While it is generally well-tolerated, there are some potential side effects that patients should be aware of.
One of the less common side effects of nicorandil is stomatitis and oral ulceration. This can be uncomfortable and may require medical attention. However, most patients do not experience this side effect.
Nicorandil works by relaxing vascular smooth muscle, which reduces ventricular filling pressure and myocardial workload. This can be beneficial for patients with angina, but it can also cause hypotension (low blood pressure) in some cases.
Another mechanism of action for nicorandil is its ability to activate ATP-dependent potassium channels in the mitochondria of the myocardium. This can help to improve cardiac function and reduce the risk of ischemia (lack of oxygen to the heart).
The most common side effect of nicorandil therapy is headache, which affects up to 48% of patients. This side effect is usually transient and can be managed by starting with a lower initial dose. Patients who are susceptible to headaches should be monitored closely.
Finally, it is important to note that concomitant use of sildenafil (Viagra) with nicorandil should be avoided. This is because sildenafil can significantly enhance the hypotensive effect of nicorandil, which can be dangerous for some patients.
In summary, nicorandil is a useful medication for treating angina, but patients should be aware of its potential side effects and should always follow their doctor’s instructions for use.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 19
Correct
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A 65-year-old man presents to the emergency department with severe chest pain that started an hour ago and is radiating to his left arm. He has a history of type two diabetes and has smoked 50 packs of cigarettes in his lifetime. An ECG shows ST-elevation in leads V2-4, indicating a STEMI. As the healthcare provider, you decide to initiate treatment and give the patient 300mg of aspirin orally. What is the mechanism of action of this medication?
Your Answer: Non-reversible COX 1 and 2 inhibitor
Explanation:Aspirin irreversibly inhibits both COX 1 and COX 2, preventing the conversion of arachidonic acid into prostaglandin, prostacyclin, and thromboxane. Thromboxane A2 is responsible for platelet aggregation and vasoconstriction. In cases of acute coronary syndrome, high doses of aspirin are administered to prevent the enlargement of the coronary thrombus.
The Mechanism and Guidelines for Aspirin Use in Cardiovascular Disease
Aspirin is a medication that works by blocking the action of cyclooxygenase-1 and 2, which are responsible for the synthesis of prostaglandin, prostacyclin, and thromboxane. By inhibiting the formation of thromboxane A2 in platelets, aspirin reduces their ability to aggregate, making it a widely used medication in cardiovascular disease. However, recent trials have cast doubt on the use of aspirin in primary prevention of cardiovascular disease, leading to changes in guidelines. Aspirin is now recommended as a first-line treatment for patients with ischaemic heart disease, but it should not be used in children under 16 due to the risk of Reye’s syndrome. The medication can also potentiate the effects of oral hypoglycaemics, warfarin, and steroids.
The Medicines and Healthcare products Regulatory Agency (MHRA) issued a drug safety update in January 2010, reminding prescribers that aspirin is not licensed for primary prevention. NICE now recommends clopidogrel as a first-line treatment following an ischaemic stroke and for peripheral arterial disease. However, the situation is more complex for TIAs, with recent Royal College of Physician (RCP) guidelines supporting the use of clopidogrel, while older NICE guidelines still recommend aspirin + dipyridamole – a position the RCP state is ‘illogical’. Despite these changes, aspirin remains an important medication in the treatment of cardiovascular disease, and its use should be carefully considered based on individual patient needs and risk factors.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 20
Incorrect
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A 35-year-old woman is recommended varenicline to aid in her smoking cessation. What is the mechanism of action of varenicline?
Your Answer: Norepinephrine and dopamine reuptake inhibitor, and nicotinic antagonist
Correct Answer: Nicotinic receptor partial agonist
Explanation:NICE guidance recommends offering nicotine replacement therapy (NRT), varenicline, or bupropion to patients for smoking cessation, with no preference for one medication over another. NRT should be offered in combination for those with high nicotine dependence or inadequate response to single forms. Varenicline should be started a week before the target stop date and monitored for adverse effects, including nausea and suicidal behavior. Bupropion should also be started before the target stop date and is contraindicated in epilepsy, pregnancy, and breastfeeding. Pregnant women should be tested for smoking and referred to NHS Stop Smoking Services, with first-line interventions being cognitive behavior therapy, motivational interviewing, or structured self-help and support. NRT may be used if other measures fail, but varenicline and bupropion are contraindicated.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 21
Correct
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A 42-year-old woman with epilepsy complains of hair loss and tremors. Her husband reports that she has become more irritable since starting her medication.
Which medication is the most likely culprit?Your Answer: Sodium valproate (Epilim®)
Explanation:Common Side Effects of Anticonvulsants and Analysis of Symptoms Associated with Different Medications
Anticonvulsants are commonly used to treat seizures, but they can also have side effects. One of the most common side effects of sodium valproate is hair loss, along with aggression and tremors. Levetiracetam is commonly associated with aggression and tremors, but rarely with alopecia. Carbamazepine is rarely associated with aggression or alopecia, and lamotrigine is commonly associated with aggression and tremors but not hair loss. Phenytoin is commonly associated with tremors but not the other symptoms mentioned. This analysis can help identify which medication may be causing certain symptoms. Other common side effects of anticonvulsants include fatigue, skin rashes, and gastrointestinal issues. It is important to consult with a healthcare provider about any concerns regarding medication side effects.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 22
Correct
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You are contemplating prescribing mefloquine as a prophylaxis for malaria for a 26-year-old female. What is the most crucial contraindication to keep in mind?
Your Answer: A history of anxiety or depression
Explanation:Strengthened Warnings on the Neuropsychiatric Side-Effects of Mefloquine
Mefloquine, also known as Lariam, is a medication used for the prevention and treatment of certain types of malaria. However, there has been a long-standing concern about its potential neuropsychiatric side-effects. A recent review has led to strengthened warnings about the risks associated with mefloquine.
Patients taking mefloquine may experience side-effects such as nightmares or anxiety, which could be a warning sign of a more serious neuropsychiatric event. There have been reports of suicide and deliberate self-harm in patients taking mefloquine. Adverse reactions may also continue for several months due to the long half-life of the medication.
It is important to note that mefloquine should not be used in patients with a history of anxiety, depression, schizophrenia, or other psychiatric disorders. If patients experience any neuropsychiatric side-effects while taking mefloquine, they should stop taking the medication and seek medical advice. These strengthened warnings aim to ensure that patients are fully informed about the potential risks associated with mefloquine.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 23
Incorrect
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What statement regarding the pharmacology of trimethoprim is correct? Choose only one option from the list.
Your Answer: It may cause marrow depression and microcytic anaemia
Correct Answer: It can be combined with sulfamethoxazole for synergistic reasons
Explanation:Understanding Trimethoprim: Uses, Synergy, and Potential Side Effects
Trimethoprim is an antimicrobial drug that is commonly used to treat urinary tract infections and prevent Pneumocystis jirovecii pneumonia. It works by inhibiting the reduction of dihydrofolic acid to tetrahydrofolic acid, which is essential for bacterial DNA synthesis. While it is often combined with sulfamethoxazole for synergistic reasons, serum level monitoring is not required for dosage guidance. However, caution should be exercised in individuals with a predisposition to folate deficiency, as trimethoprim can lower folic acid levels and lead to megaloblastic anemia. While hepatic toxicity has not been reported, it is important to be aware of potential side effects when using this medication.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 24
Incorrect
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A 61-year-old man with a history of type 2 diabetes mellitus and benign prostatic hypertrophy experiences urinary retention and an acute kidney injury. Which medication should be discontinued?
Your Answer: Gliclazide
Correct Answer: Metformin
Explanation:Due to the risk of lactic acidosis, metformin should be discontinued as the patient has developed an acute kidney injury. Additionally, in the future, it may be necessary to discontinue paroxetine as SSRIs can exacerbate urinary retention.
Metformin is a medication commonly used to treat type 2 diabetes mellitus. It belongs to a class of drugs called biguanides and works by activating the AMP-activated protein kinase (AMPK), which increases insulin sensitivity and reduces hepatic gluconeogenesis. Additionally, it may decrease the absorption of carbohydrates in the gastrointestinal tract. Unlike other diabetes medications, such as sulphonylureas, metformin does not cause hypoglycemia or weight gain, making it a first-line treatment option, especially for overweight patients. It is also used to treat polycystic ovarian syndrome and non-alcoholic fatty liver disease.
While metformin is generally well-tolerated, gastrointestinal side effects such as nausea, anorexia, and diarrhea are common and can be intolerable for some patients. Reduced absorption of vitamin B12 is also a potential side effect, although it rarely causes clinical problems. In rare cases, metformin can cause lactic acidosis, particularly in patients with severe liver disease or renal failure. However, it is important to note that lactic acidosis is now recognized as a rare side effect of metformin.
There are several contraindications to using metformin, including chronic kidney disease, recent myocardial infarction, sepsis, acute kidney injury, severe dehydration, and alcohol abuse. Additionally, metformin should be discontinued before and after procedures involving iodine-containing x-ray contrast media to reduce the risk of contrast nephropathy.
When starting metformin, it is important to titrate the dose slowly to reduce the incidence of gastrointestinal side effects. If patients experience intolerable side effects, modified-release metformin may be considered as an alternative.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 25
Incorrect
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A 56-year-old woman with a lengthy history of rheumatoid arthritis presents to the clinic with a chief complaint of dyspnea. During the examination, her oxygen saturation is found to be 92% on room air, and spirometry reveals a restrictive pattern accompanied by a decreased transfer factor. Which medication is the most probable cause of her symptoms?
Your Answer: Ciclosporin
Correct Answer: Methotrexate
Explanation:The use of methotrexate as well as other anti-rheumatoid drugs like sulfasalazine and gold may lead to the development of lung fibrosis in patients. This patient is currently experiencing pulmonary fibrosis which could be attributed to the use of methotrexate.
Drugs that can lead to lung fibrosis
Lung fibrosis is a condition where the lung tissue becomes scarred and thickened, making it difficult for the lungs to function properly. There are several drugs that can cause lung fibrosis as a side effect. These drugs include amiodarone, which is used to treat heart rhythm problems, cytotoxic agents such as busulphan and bleomycin, which are used to treat cancer, and anti-rheumatoid drugs like methotrexate and sulfasalazine. Nitrofurantoin, an antibiotic used to treat urinary tract infections, and ergot-derived dopamine receptor agonists like bromocriptine, cabergoline, and pergolide, which are used to treat Parkinson’s disease, can also cause lung fibrosis. It is important to be aware of the potential side effects of these drugs and to discuss any concerns with a healthcare provider. Proper monitoring and management can help prevent or minimize the risk of lung fibrosis.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 26
Incorrect
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A 25-year-old female is prescribed varenicline to aid in smoking cessation. What is the most probable adverse effect that may occur?
Your Answer: Vivid dreams
Correct Answer: Nausea
Explanation:NICE guidance recommends offering nicotine replacement therapy (NRT), varenicline, or bupropion to patients for smoking cessation, with no preference for one medication over another. NRT should be offered in combination for those with high nicotine dependence or inadequate response to single forms. Varenicline should be started a week before the target stop date and monitored for adverse effects, including nausea and suicidal behavior. Bupropion should also be started before the target stop date and is contraindicated in epilepsy, pregnancy, and breastfeeding. Pregnant women should be tested for smoking and referred to NHS Stop Smoking Services, with first-line interventions being cognitive behavior therapy, motivational interviewing, or structured self-help and support. NRT may be used if other measures fail, but varenicline and bupropion are contraindicated.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 27
Correct
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Prolonged use of which drug can result in tachyphylaxis, which is an acute and sudden decrease in response to a drug after its administration, leading to a rapid and short-term onset of drug tolerance?
Your Answer: Xylometazoline (eg Sudafed® nasal spray)
Explanation:Common Drugs and Tachyphylaxis: Understanding the Risk
Nasal decongestants, such as xylometazoline, are often used to relieve nasal congestion. However, prolonged use can lead to rebound congestion, known as rhinitis medicamentosa. Amiodarone, an antiarrhythmic drug, has a long half-life and potential for drug interactions even after treatment has stopped. Metronidazole, an antimicrobial drug, can be absorbed systemically and may interact with other medications. Naproxen, a non-steroidal anti-inflammatory drug, has no evidence of tachyphylaxis. Phenoxymethylpenicillin, an antibiotic, is not associated with tachyphylaxis. Understanding the risk of tachyphylaxis with common drugs is important for safe and effective use.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 28
Correct
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A 42-year-old man experiences a sudden onset of migraine and is administered a subcutaneous injection of sumatriptan, resulting in the alleviation of his symptoms.
What is the mechanism of action of the drug?Your Answer: Causing vasoconstriction of cranial arteries
Explanation:Understanding the Mechanisms of Sumatriptan: A Migraine and Cluster Headache Treatment
Sumatriptan is a medication commonly used to treat migraine and cluster headaches. It works by activating specific serotonin receptors (5-HT1D and 5-HT1B) found on cranial and basilar arteries, causing vasoconstriction of these blood vessels. This medication can be administered orally, by subcutaneous injection, or intranasally.
It is important to note that sumatriptan has no effect on adrenergic receptors or acetylcholinesterase receptors. It is also not a cyclooxygenase (COX) inhibitor or an opioid receptor agonist or antagonist.
In addition to its effects on blood vessels, sumatriptan has been shown to decrease the activity of the trigeminal nerve, which is responsible for its effectiveness in treating cluster headaches.
Overall, understanding the mechanisms of sumatriptan can help healthcare professionals and patients better understand how this medication works to alleviate the symptoms of migraine and cluster headaches.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 29
Correct
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A 25-year-old student is brought to the clinic by his companions as he appears confused. They mention that he has been experiencing headaches for the past few weeks. During the examination, he has a low-grade fever and his mucosa is unusually pink. What is the probable diagnosis?
Your Answer: Carbon monoxide poisoning
Explanation:Typical symptoms of carbon monoxide poisoning include confusion and pink mucosae, with a low-grade fever being present in only a small number of cases.
Understanding Carbon Monoxide Poisoning
Carbon monoxide poisoning occurs when carbon monoxide, a toxic gas, is inhaled and binds to haemoglobin and myoglobin in the body, resulting in tissue hypoxia. This leads to a left-shift of the oxygen dissociation curve, causing a decrease in oxygen saturation of haemoglobin. In the UK, there are approximately 50 deaths per year from accidental carbon monoxide poisoning.
Symptoms of carbon monoxide toxicity include headache, nausea and vomiting, vertigo, confusion, and subjective weakness. Severe toxicity can result in pink skin and mucosae, hyperpyrexia, arrhythmias, extrapyramidal features, coma, and even death.
To diagnose carbon monoxide poisoning, pulse oximetry may not be reliable due to similarities between oxyhaemoglobin and carboxyhaemoglobin. Therefore, a venous or arterial blood gas should be taken to measure carboxyhaemoglobin levels. Non-smokers typically have levels below 3%, while smokers have levels below 10%. Symptomatic patients have levels between 10-30%, and severe toxicity is indicated by levels above 30%. An ECG may also be useful to check for cardiac ischaemia.
In the emergency department, patients with suspected carbon monoxide poisoning should receive 100% high-flow oxygen via a non-rebreather mask. This decreases the half-life of carboxyhemoglobin and should be administered as soon as possible, with treatment continuing for a minimum of six hours. Target oxygen saturations are 100%, and treatment is generally continued until all symptoms have resolved. For more severe cases, hyperbaric oxygen therapy may be considered, as it has been shown to have better long-term outcomes than standard oxygen therapy. Indications for hyperbaric oxygen therapy include loss of consciousness, neurological signs other than headache, myocardial ischaemia or arrhythmia, and pregnancy.
Overall, understanding the pathophysiology, symptoms, and management of carbon monoxide poisoning is crucial in preventing and treating this potentially deadly condition.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 30
Correct
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A 55-year-old woman visits her GP seeking advice on starting hormone replacement therapy (HRT) due to distressing vasomotor symptoms. Her LMP was 10 months ago, and she has not undergone any surgeries, has no significant medical history, and is not sexually active. Despite making lifestyle changes, she has not experienced much relief. Assuming there are no contraindications, what treatment would you suggest?
Your Answer: Cyclical combined HRT
Explanation:When a woman expresses interest in starting hormone replacement therapy (HRT), it is important to gather a detailed medical history to determine her menopausal status. This includes information about her last menstrual period (LMP) and any bleeding patterns leading up to it. Based on this information, it appears that the woman in question is peri-menopausal, as she has not been without a period for a full year.
The primary reason for starting HRT is to alleviate vasomotor symptoms, such as hot flashes. However, it may also be used to prevent osteoporosis in women who have been diagnosed with premature menopause.
For women who still have a uterus, HRT should consist of a combination of estrogen and progesterone. The progesterone is essential for reducing the risk of endometrial cancer, which can occur when estrogen is used alone. Women who have had a hysterectomy will typically receive continuous estrogen-only therapy.
The type of HRT prescribed will depend on the woman’s menopausal status. Those who have had their LMP within the past year should receive cyclical combined HRT, while those who have been without a period for at least a year or who have experienced premature menopause should receive continuous combined HRT.
For women who are unable or unwilling to take HRT, there are several non-hormonal treatments available for vasomotor symptoms. These include certain selective serotonin and noradrenaline reuptake inhibitors, clonidine, and gabapentin. However, sertraline is not effective for treating hot flashes. It is worth noting that the National Institute for Health and Clinical Excellence (NICE) does not recommend the use of herbal or complementary therapies for managing hot flashes and night sweats.
Hormone replacement therapy (HRT) involves a small dose of oestrogen and progestogen to alleviate menopausal symptoms. The indications for HRT have changed due to the long-term risks, and it is primarily used for vasomotor symptoms and preventing osteoporosis in younger women. HRT consists of natural oestrogens and synthetic progestogens, and can be taken orally or transdermally. Transdermal is preferred for women at risk of venous thromboembolism.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 31
Correct
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A 28-year-old woman who is 16 weeks' pregnant complains of frequent urination. Urinalysis confirms the presence of nitrites and leukocytes.
What is the most appropriate antibiotic to prescribe?Your Answer: Nitrofurantoin
Explanation:Management of Urinary Tract Infections in Pregnancy: Antibiotic Options and Guidelines
Urinary tract infections (UTIs) are common during pregnancy and require prompt treatment to prevent complications. The current UK antimicrobial guidelines recommend nitrofurantoin as the first-line treatment for UTIs in pregnancy, with amoxicillin as an alternative if the microorganism is susceptible to it. Trimethoprim should be avoided due to its teratogenicity risk, while ciprofloxacin is only used for specific cases. Vancomycin is reserved for severe cases of Clostridium difficile infection. Symptomatic relief with paracetamol can also be offered. Urine cultures should be sent before starting empirical antibiotic treatment and as a test of cure after treatment completion. Follow-up is necessary to check treatment response and culture results. This article provides a comprehensive overview of the antibiotic options and guidelines for managing UTIs in pregnancy.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 32
Correct
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A 30-year-old woman has been diagnosed with Graves disease and has been prescribed carbimazole. What is the most severe side effect of carbimazole?
Your Answer: Reversible agranulocytosis
Explanation:Carbimazole: Side Effects and Mechanism of Action
Carbimazole is a medication used to treat hyperthyroidism by inhibiting the production of thyroid hormones. However, it can also cause several side effects that patients should be aware of.
The most serious side effect is bone marrow suppression, which can lead to neutropenia and agranulocytosis. Patients should report any symptoms of infection immediately, as routine monitoring of white cell count is not useful. Cholestatic jaundice and drug-induced hepatitis are also possible side effects, but usually reversible upon discontinuation of the drug. Hypoprothrombinaemia, a rare side effect, can increase the risk of bleeding in patients on anticoagulant therapy.
Carbimazole works by inhibiting the enzyme thyroperoxidase, which is responsible for the synthesis of thyroid hormones. However, its onset of clinical effects is slow because it takes time to deplete the large store of pre-formed thyroid hormones in the thyroid gland.
In addition to its anti-thyroid effect, carbimazole also has a modest immunosuppressive activity, reduces the serum level of thyroid-stimulating hormone antibody, and can cause a reduction in clotting factor prothrombin. However, these effects are not thought to contribute significantly to its efficacy.
Overall, patients taking carbimazole should be aware of its potential side effects and report any symptoms to their healthcare provider promptly.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 33
Incorrect
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Which of the following drugs is most commonly associated with peripheral neuropathy in the treatment of tuberculosis, and how does it affect patients of different ages?
Your Answer: Pyrazinamide
Correct Answer: Isoniazid
Explanation:Side-Effects and Mechanism of Action of Tuberculosis Drugs
Rifampicin is a drug that inhibits bacterial DNA dependent RNA polymerase, which prevents the transcription of DNA into mRNA. However, it is a potent liver enzyme inducer and can cause hepatitis, orange secretions, and flu-like symptoms.
Isoniazid, on the other hand, inhibits mycolic acid synthesis. It can cause peripheral neuropathy, which can be prevented with pyridoxine (Vitamin B6). It can also cause hepatitis and agranulocytosis. Additionally, it is a liver enzyme inhibitor.
Pyrazinamide is converted by pyrazinamidase into pyrazinoic acid, which in turn inhibits fatty acid synthase (FAS) I. However, it can cause hyperuricaemia, leading to gout, as well as arthralgia, myalgia, and hepatitis.
Lastly, Ethambutol inhibits the enzyme arabinosyl transferase, which polymerizes arabinose into arabinan. It can cause optic neuritis, so it is important to check visual acuity before and during treatment. Additionally, the dose needs adjusting in patients with renal impairment.
In summary, these tuberculosis drugs have different mechanisms of action and can cause various side-effects. It is important to monitor patients closely and adjust treatment accordingly to ensure the best possible outcomes.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 34
Incorrect
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A 75-year-old man presents to the emergency department with nosebleeds, extensive bruising, and mucosal bleeding. His vital signs are stable, and laboratory results reveal a platelet count of 23 * 109/L (150 - 400), which is significantly lower than his previous blood test taken a week ago. The patient reports taking a new medication for nocturnal leg cramps. Which of the following medications could be responsible for his thrombocytopenia?
Your Answer: Ropinirole
Correct Answer: Quinine
Explanation:Quinine is the only medication in this list that is strongly linked to the development of drug-induced thrombocytopaenia. However, excessive consumption of tonic water containing quinine can also lead to this condition in certain individuals. While all the other medications in the list can be used to treat nocturnal leg cramps, they do not have a significant association with thrombocytopaenia.
Understanding Drug-Induced Thrombocytopenia
Drug-induced thrombocytopenia is a condition where a person’s platelet count drops due to the use of certain medications. This type of thrombocytopenia is believed to be immune-mediated, meaning that the body’s immune system mistakenly attacks and destroys platelets. Some of the drugs that can cause this condition include quinine, abciximab, NSAIDs, diuretics like furosemide, antibiotics such as penicillins, sulphonamides, and rifampicin, anticonvulsants like carbamazepine and valproate, and heparin.
It is important to note that not everyone who takes these medications will develop drug-induced thrombocytopenia. However, those who do may experience symptoms such as easy bruising, bleeding gums, nosebleeds, and prolonged bleeding from cuts. In severe cases, the condition can lead to life-threatening bleeding.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 35
Correct
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An 85-year-old woman presents with a history of falls. She has a medical history of osteoporosis, constipation, frequent urinary tract infections, ischaemic heart disease, and urge incontinence. Upon conducting a comprehensive assessment, you determine that her falls are likely due to a combination of physical frailty, poor balance, and medication burden. Which medication should be discontinued first?
Your Answer: Oxybutynin
Explanation:To avoid the risk of falls, it is not recommended to administer oxybutynin to frail elderly individuals. Instead, safer alternatives such as solifenacin and tolterodine should be considered. Mirabegron, a newer medication, may also be a viable option as it is believed to have fewer anti-cholinergic side effects. Discontinuing laxatives may not be helpful if the patient is still experiencing constipation. However, prescribing alendronic acid for osteoporosis and aspirin for ischaemic heart disease is appropriate given the patient’s medical history and risk of falls. While the use of trimethoprim as long-term prophylaxis for urinary tract infections is controversial, it should not be the first intervention to be discontinued.
Understanding Urinary Incontinence: Causes, Classification, and Management
Urinary incontinence (UI) is a common condition that affects around 4-5% of the population, with elderly females being more susceptible. Several risk factors contribute to UI, including advancing age, previous pregnancy and childbirth, high body mass index, hysterectomy, and family history. UI can be classified into different types, such as overactive bladder (OAB)/urge incontinence, stress incontinence, mixed incontinence, overflow incontinence, and functional incontinence.
Initial investigation of UI involves completing bladder diaries for at least three days, vaginal examination, urine dipstick and culture, and urodynamic studies. Management of UI depends on the predominant type of incontinence. For urge incontinence, bladder retraining and bladder stabilizing drugs such as antimuscarinics are recommended. For stress incontinence, pelvic floor muscle training and surgical procedures such as retropubic mid-urethral tape procedures may be offered. Duloxetine, a combined noradrenaline and serotonin reuptake inhibitor, may also be used as an alternative to surgery.
In summary, understanding the causes, classification, and management of UI is crucial in providing appropriate care for patients. Early diagnosis and intervention can significantly improve the quality of life for those affected by this condition.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 36
Correct
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A 29-year-old male arrives at the Emergency Department complaining of feeling extremely sick. He reports that his GP had prescribed him antibiotics for a chest infection. Upon examination, an ECG reveals polymorphic ventricular tachycardia (torsades de pointes). What medication is he likely taking?
Your Answer: Clarithromycin
Explanation:Torsades de pointes can be caused by macrolides, particularly clarithromycin, due to its potential to prolong the QT interval and trigger polymorphic ventricular tachycardia. This risk is higher in patients with an underlying channelopathy. Long QT syndrome can be caused by genetic factors such as potassium or sodium channel mutations, as well as electrolyte imbalances like hypocalcaemia, hypomagnesaemia, and hypokalaemia. Certain drugs, including antiarrhythmics, antibiotics, and psychotropic medications, can also cause long QT syndrome.
Torsades de Pointes: A Life-Threatening Condition
Torsades de pointes is a type of ventricular tachycardia that is associated with a prolonged QT interval. This condition can lead to ventricular fibrillation, which can cause sudden death. There are several causes of a prolonged QT interval, including congenital conditions such as Jervell-Lange-Nielsen syndrome and Romano-Ward syndrome, as well as certain medications like antiarrhythmics, tricyclic antidepressants, and antipsychotics. Other causes include electrolyte imbalances, myocarditis, hypothermia, and subarachnoid hemorrhage.
The management of torsades de pointes involves the administration of intravenous magnesium sulfate. This can help to stabilize the heart rhythm and prevent further complications.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 37
Correct
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As a junior doctor on a night shift in the emergency department of a district general hospital, you receive a 59-year-old man via ambulance who is complaining of chest pain and shortness of breath. After performing an A-E assessment, you find that his airway is patent, he is tachypnoeic with equal chest expansion, he is tachycardic with a blood pressure of 100/70 mmHg, he is alert with normal blood glucose and apyrexial. An ECG reveals ST-segment elevation in the anterior chest leads. Due to the nearest PCI center being over 3 hours away, it is decided that he will receive fibrinolysis.
What is the medication that should be administered before this treatment?Your Answer: Fondaparinux
Explanation:When treating ST-elevation myocardial infarctions with fibrinolysis, it is recommended to also administer an antithrombin drug. This is especially important when percutaneous coronary intervention cannot be performed within 120 minutes, which is often the case in district general hospitals. Ramipril, an ACE inhibitor, is not used in the acute management of acute coronary syndrome, but rather for hypertension, heart failure, and secondary prevention following a myocardial infarction. Low-dose aspirin (75mg) is not indicated for acute myocardial infarction, but rather for primary and secondary prevention. The recommended dose for STEMI management is 300 mg. Fondaparinux, an antithrombin medication, is used to prevent the clot from getting bigger by activating antithrombin 3, which causes the inactivation of factor Xa. It should be administered before fibrinolysis. Morphine, historically used for pain control in ACS, has been found to increase mortality and should only be used for severe pain control.
Managing Acute Coronary Syndrome: A Summary of NICE Guidelines
Acute coronary syndrome (ACS) is a common and serious medical condition that requires prompt management. The management of ACS has evolved over the years, with the development of new drugs and procedures such as percutaneous coronary intervention (PCI). The National Institute for Health and Care Excellence (NICE) has updated its guidelines on the management of ACS in 2020.
ACS can be classified into three subtypes: ST-elevation myocardial infarction (STEMI), non ST-elevation myocardial infarction (NSTEMI), and unstable angina. The management of ACS depends on the subtype. However, there are common initial drug therapies for all patients with ACS, such as aspirin and nitrates. Oxygen should only be given if the patient has oxygen saturations below 94%, and morphine should only be given for severe pain.
For patients with STEMI, the first step is to assess eligibility for coronary reperfusion therapy, which can be either PCI or fibrinolysis. Patients with NSTEMI/unstable angina require a risk assessment using the Global Registry of Acute Coronary Events (GRACE) tool to determine whether they need coronary angiography (with follow-on PCI if necessary) or conservative management.
This summary provides an overview of the NICE guidelines for managing ACS. The guidelines are complex and depend on individual patient factors, so healthcare professionals should review the full guidelines for further details. Proper management of ACS can improve patient outcomes and reduce the risk of complications.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 38
Incorrect
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A Foundation Year 1 doctor stops you in the corridor to ask for some advice about prescribing and unwanted pharmacological effects of drugs in pregnancy.
Which of the following list of potential pharmacological risks of drugs in pregnancy is true?Your Answer: Thiazide diuretics : Neonatal polycythaemia
Correct Answer: Aspirin : kernicterus
Explanation:Various drugs can have negative effects on pregnancy beyond the risk of birth defects. For example, aspirin should be used with caution in the third trimester due to the potential for impaired platelet function, hemorrhage, and increased blood loss during labor. High doses of aspirin may also lead to intrauterine growth restriction, closure of the fetal ductus arteriosus, and persistent pulmonary hypertension in newborns. Similarly, ACE inhibitors should be avoided during pregnancy unless absolutely necessary, as they can negatively impact fetal and neonatal blood pressure control and renal function. Thiazide diuretics should not be used to treat gestational hypertension, as they can cause neonatal thrombocytopenia, bone marrow suppression, jaundice, electrolyte imbalances, and hypoglycemia. NSAIDs should also be avoided during pregnancy unless the potential benefits outweigh the risks, as they can lead to closure of the fetal ductus arteriosus and delayed onset and increased duration of labor. Other drugs, such as b-blockers and carbimazole, can also have negative effects on pregnancy and should be used with caution.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 39
Correct
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Which of the following relating to St John's Wort is not true?
Your Answer: Causes inhibition of the P450 system
Explanation:The P450 system is known to be induced by St John’s Wort.
St John’s Wort: An Alternative Treatment for Mild-Moderate Depression
St John’s Wort has been found to be as effective as tricyclic antidepressants in treating mild-moderate depression. Its mechanism of action is thought to be similar to SSRIs, although it has also been shown to inhibit noradrenaline uptake. However, the National Institute for Health and Care Excellence (NICE) advises against its use due to uncertainty about appropriate doses, variation in the nature of preparations, and potential serious interactions with other drugs.
In clinical trials, the adverse effects of St John’s Wort were similar to those of a placebo. However, it can cause serotonin syndrome and is an inducer of the P450 system, which can lead to decreased levels of drugs such as warfarin and ciclosporin. Additionally, the effectiveness of the combined oral contraceptive pill may be reduced.
Overall, St John’s Wort may be a viable alternative treatment for those with mild-moderate depression. However, caution should be exercised due to potential interactions with other medications and the lack of standardization in dosing and preparation. It is important to consult with a healthcare professional before starting any new treatment.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 40
Incorrect
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A 42-year-old woman is admitted to hospital with left-sided weakness. She takes warfarin for deep vein thrombosis and her international normalised ratio (INR) is usually in the therapeutic range of 2–3. Her INR is measured on admission to hospital and is 1.1. She has recently started a new medication.
Which of the following medications is this patient most likely to have recently started?
Your Answer: Ketoconazole
Correct Answer: Carbamazepine
Explanation:Cytochrome P450 Enzyme Inducers and Inhibitors and their Effects on Warfarin Metabolism
Warfarin is a commonly used anticoagulant medication that requires careful monitoring of the international normalized ratio (INR) to ensure therapeutic efficacy and prevent bleeding complications. However, certain medications can affect the metabolism of warfarin by inducing or inhibiting cytochrome P450 enzymes in the liver.
One example of a cytochrome P450 enzyme inducer is carbamazepine, which can increase warfarin metabolism and reduce its effectiveness. This can result in a decreased INR and potentially increase the risk of blood clots. On the other hand, cytochrome P450 enzyme inhibitors such as cimetidine, erythromycin, ketoconazole, and sulfamethoxazole can reduce warfarin metabolism and increase its potency, leading to an increased INR and higher risk of bleeding complications.
To remember these medications, a helpful mnemonic is PC BRAS for enzyme inducers and SICKFACES.COM for enzyme inhibitors. Patients starting these medications should be closely monitored for changes in their INR and warfarin dosages may need to be adjusted accordingly.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 41
Correct
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A 70-year-old male has been admitted to the cardiology ward following his presentation to the emergency department with palpitations and dyspnoea. After further investigations, he was diagnosed with atrial fibrillation and prescribed digoxin for rate control. What is the recommended frequency for routine drug monitoring in this case?
Your Answer: No routine monitoring required
Explanation:Digoxin levels do not require regular monitoring, unless there is suspicion of toxicity. As this patient is commencing digoxin and has no signs of toxicity, routine monitoring is unnecessary. It is not necessary to measure digoxin levels every month until they have stabilized, nor is it appropriate to monitor the drug every 2 weeks for the first 3 months. Routine monitoring is also not required annually throughout the course of treatment.
Understanding Digoxin and Its Toxicity
Digoxin is a medication used for rate control in atrial fibrillation and for improving symptoms in heart failure patients. It works by decreasing conduction through the atrioventricular node and increasing the force of cardiac muscle contraction. However, it has a narrow therapeutic index and requires monitoring for toxicity.
Toxicity may occur even when the digoxin concentration is within the therapeutic range. Symptoms of toxicity include lethargy, nausea, vomiting, anorexia, confusion, yellow-green vision, arrhythmias, and gynaecomastia. Hypokalaemia is a classic precipitating factor, as it allows digoxin to more easily bind to the ATPase pump and increase its inhibitory effects. Other factors that may contribute to toxicity include increasing age, renal failure, myocardial ischaemia, electrolyte imbalances, hypoalbuminaemia, hypothermia, hypothyroidism, and certain medications such as amiodarone, quinidine, and verapamil.
Management of digoxin toxicity involves the use of Digibind, correction of arrhythmias, and monitoring of potassium levels. It is important to recognize the potential for toxicity and monitor patients accordingly to prevent adverse outcomes.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 42
Correct
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A 68-year-old man comes to the Emergency Department with severe inflammation of his first metatarsophalangeal joint. He reports swelling and tenderness of the joint and a sample of fluid is sent for microscopy. He has a medical history of hypertension and duodenal ulcers.
What is the most suitable initial medication to prescribe?
Choose ONE option from the list provided.Your Answer: Colchicine
Explanation:Managing Gout: Treatment Options and Contraindications
Gout is a type of arthritis caused by the deposition of urate crystals in the synovial fluid. Chronic hyperuricemia is the primary cause of this condition. The acute management of gout involves the use of non-steroidal anti-inflammatory drugs (NSAIDs) or colchicine as first-line treatment. However, the maximum dose of NSAIDs should be prescribed until 1-2 days after the symptoms have settled, and gastroprotection may also be necessary. Colchicine has a slower onset of action and may cause diarrhea as a side effect. Oral steroids or intra-articular steroid injections may be considered if NSAIDs and colchicine are contraindicated. Allopurinol is not recommended during the acute phase but is useful for preventing recurrent attacks of gout. Diclofenac and indomethacin are contraindicated in patients with duodenal ulcers, and colchicine is a suitable alternative for the treatment of gout. Diazepam, a benzodiazepine, is not useful in the treatment of gout as it does not have anti-inflammatory or analgesic properties.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 43
Incorrect
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A 50-year-old man with Down's syndrome presents to you with a recent diagnosis of essential hypertension. He is accompanied by his caregiver and expresses his fear of needles, requesting medication that does not require regular blood tests. Which of the following medications would be appropriate for him?
Your Answer: Ramipril
Correct Answer: Amlodipine
Explanation:Regular monitoring of renal function and electrolytes is necessary for both Ramipril, an ACE inhibitor, and Candesartan, an angiotensin 2 receptor blocker.
Understanding Calcium Channel Blockers
Calcium channel blockers are medications primarily used to manage cardiovascular diseases. These blockers target voltage-gated calcium channels present in myocardial cells, cells of the conduction system, and vascular smooth muscle cells. The different types of calcium channel blockers have varying effects on these three areas, making it crucial to differentiate their uses and actions.
Verapamil is an example of a calcium channel blocker used to manage angina, hypertension, and arrhythmias. However, it is highly negatively inotropic and should not be given with beta-blockers as it may cause heart block. Verapamil may also cause side effects such as heart failure, constipation, hypotension, bradycardia, and flushing.
Diltiazem is another calcium channel blocker used to manage angina and hypertension. It is less negatively inotropic than verapamil, but caution should still be exercised when patients have heart failure or are taking beta-blockers. Diltiazem may cause side effects such as hypotension, bradycardia, heart failure, and ankle swelling.
On the other hand, dihydropyridines such as nifedipine, amlodipine, and felodipine are calcium channel blockers used to manage hypertension, angina, and Raynaud’s. These blockers affect the peripheral vascular smooth muscle more than the myocardium, resulting in no worsening of heart failure but may cause ankle swelling. Shorter-acting dihydropyridines such as nifedipine may cause peripheral vasodilation, resulting in reflex tachycardia and side effects such as flushing, headache, and ankle swelling.
In summary, understanding the different types of calcium channel blockers and their effects on the body is crucial in managing cardiovascular diseases. It is also important to note the potential side effects and cautions when prescribing these medications.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 44
Correct
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Amiodarone is known to cause which side effect? Choose ONE option from the list provided.
Your Answer: Hyperthyroidism
Explanation:Understanding the Side Effects of Amiodarone: A Comprehensive Overview
Amiodarone is a medication commonly used to treat cardiac arrhythmias. However, it is important to be aware of its potential side effects. Here is a breakdown of some of the most important things to know:
Hyperthyroidism: Amiodarone can cause both hypo and hyperthyroidism. Patients taking this medication should have their thyroid function checked regularly.
COPD: While amiodarone is not known to cause COPD, it can lead to pulmonary toxicity, including pneumonitis and fibrosis. Patients should have yearly chest x-rays.
Drug-induced diabetes mellitus: There is no known association between amiodarone and the development of diabetes mellitus.
Drug-induced pemphigus: Long-term use of amiodarone can cause phototoxicity and skin discoloration. Patients should protect their skin from light during treatment. However, it is not known to cause drug-induced pemphigus.
Renal calculi: There is no known association between amiodarone and the development of kidney disease, including renal calculi.
Other important side effects of amiodarone include hepatotoxicity, bradycardia, phototoxicity, and development of corneal deposits. If you are taking amiodarone, it is important to be aware of these potential side effects and to discuss any concerns with your healthcare provider.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 45
Correct
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A 26-year-old female patient arrives with a sudden onset of pain at the back of her ankle while jogging, accompanied by a cracking sound. Which medication from the following list could have played a role in causing this injury?
Your Answer: Ciprofloxacin
Explanation:The patient is displaying typical symptoms of a ruptured Achilles tendon, which can be caused by ciprofloxacin. Tendon damage is a known potential side effect of quinolone antibiotics, and it seems to be a rare reaction that can occur after just 8 days of treatment.
Understanding Quinolones: Antibiotics that Inhibit DNA Synthesis
Quinolones are a type of antibiotics that are known for their bactericidal properties. They work by inhibiting DNA synthesis, which makes them effective in treating bacterial infections. Some examples of quinolones include ciprofloxacin and levofloxacin.
The mechanism of action of quinolones involves inhibiting topoisomerase II (DNA gyrase) and topoisomerase IV. However, bacteria can develop resistance to quinolones through mutations to DNA gyrase or by using efflux pumps that reduce the concentration of quinolones inside the cell.
While quinolones are generally safe, they can have adverse effects. For instance, they can lower the seizure threshold in patients with epilepsy and cause tendon damage, including rupture, especially in patients taking steroids. Additionally, animal models have shown that quinolones can damage cartilage, which is why they are generally avoided in children. Quinolones can also lengthen the QT interval, which can be dangerous for patients with heart conditions.
Quinolones should be avoided in pregnant or breastfeeding women and in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Overall, understanding the mechanism of action, mechanism of resistance, adverse effects, and contraindications of quinolones is important for their safe and effective use in treating bacterial infections.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 46
Correct
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A 55-year-old man with type 2 diabetes of 8 years’ duration presents with poorly controlled blood glucose levels. He was initially started on metformin therapy and his diabetes was well controlled until the last 6 months. Despite strict adherence to diet, exercise and maximum daily doses of metformin and pioglitazone, satisfactory blood glucose control has proved difficult to achieve and the last HbA1c was at 85 mmol/mol. You consider adding the agent empagliflozin.
Managed either by lifestyle + diet
HbA1c target levels in adults with type 2 diabetes
Or
Lifestyle + diet + single drug not associated with hypoglycaemia
Managed with a drug associated with hypoglycaemia
48 mmol/mol
53 mmol/mol
Which of the following class of drugs does sitagliptin belong to?Your Answer: A dipeptidyl peptidase-4 (DPP-4) inhibitor
Explanation:Common Diabetes Medications and How They Work
Dipeptidyl peptidase-4 (DPP-4) inhibitors, such as sitagliptin, work by inhibiting the enzyme DPP-4, which breaks down hormones that stimulate insulin secretion and suppress glucagon secretion. This leads to increased insulin secretion and decreased glucagon release, helping to regulate blood glucose levels.
α-Glucosidase inhibitors, like acarbose, inhibit enzymes needed to digest carbohydrates, leading to decreased glucose absorption.
Sulfonylureas, such as tolbutamide and gliclazide, stimulate insulin release by inhibiting potassium channels in pancreatic cells.
Non-sulfonylurea insulin secretagogues, like repaglinide and nateglinide, also stimulate insulin release but act on a different binding site of the potassium channels.
Insulin sensitizers, including biguanides like metformin and thiazolidinediones (glitazones), increase glucose uptake by the cells and enhance insulin-dependent enzyme production, respectively.
Understanding the Mechanisms of Common Diabetes Medications
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 47
Correct
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A 57-year-old man with a history of bipolar disorder, which is well controlled with lithium, presents with a 2-day history of confusion, diarrhoea and tremors. He takes regular analgesia for chronic back pain and has been feeling unwell recently.
A blood test shows:
Value Reference
Lithium (serum) 4.2 mmol/L (0.6 - 1)
What is the probable reason for his symptoms?Your Answer: Ibuprofen
Explanation:NSAIDs can cause lithium toxicity by reducing renal excretion of lithium and increasing plasma levels. Therefore, routine monitoring of serum lithium levels is necessary, especially after initiation and dose changes. ACE-I and diuretics should not be used with lithium due to the risk of renal dysfunction. Abruptly stopping lithium does not cause toxicity, but reducing caffeine intake can lead to toxicity by reducing lithium clearance. Cranberry juice does not interact with lithium, but it increases the risk of rhabdomyolysis when taken with statins. Dehydration, not excessive water intake, increases the risk of lithium toxicity by reducing lithium excretion.
Understanding Lithium Toxicity
Lithium is a medication used to stabilize mood in individuals with bipolar disorder and as an adjunct in refractory depression. However, it has a narrow therapeutic range of 0.4-1.0 mmol/L and a long plasma half-life, making it crucial to monitor its levels in the blood. Lithium toxicity occurs when the concentration exceeds 1.5 mmol/L, which can be caused by dehydration, renal failure, and certain medications such as diuretics, ACE inhibitors, NSAIDs, and metronidazole.
Symptoms of lithium toxicity include a coarse tremor, hyperreflexia, acute confusion, polyuria, seizures, and even coma. It is important to manage toxicity promptly, as mild to moderate cases may respond to volume resuscitation with normal saline. However, severe cases may require hemodialysis to remove excess lithium from the body. Some healthcare providers may also use sodium bicarbonate to increase the alkalinity of the urine and promote lithium excretion, although evidence supporting its effectiveness is limited.
In summary, understanding lithium toxicity is crucial for healthcare providers and individuals taking lithium. Monitoring lithium levels in the blood and promptly managing toxicity can prevent serious complications and ensure the safe use of this medication.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 48
Correct
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A 70-year-old hypertensive man with asthma, heart failure and peptic ulcer disease reports experiencing yellowish-green halos for the past week. He has also been feeling nauseous and has lost his appetite. Despite his conditions being well controlled, physical examination reveals no abnormalities. Which of the following medications that he is taking could potentially be responsible for his current symptoms?
Your Answer: Digoxin
Explanation:Common Side Effects and Risks of Medications
Digoxin Toxicity: Symptoms and Risk Factors
Digoxin toxicity can cause vague symptoms such as anorexia, nausea, confusion, and fatigue, as well as dysrhythmias. Risk factors for toxicity include imbalances in potassium, magnesium, and calcium levels.Salbutamol: Common Side Effects and Hypokalaemia
Salbutamol may cause fine tremors, anxiety, headaches, and muscle cramps. Prolonged use or high doses can lead to hypokalaemia, which is especially concerning in patients with renal failure.Enalapril: Common Side Effects and Serious Risks
Enalapril therapy may cause raised serum creatinine, dizziness, hypotension, syncope, and dry cough. The most serious risk is angio-oedema, which can obstruct airways.Ranitidine: Common Side Effects
H2-receptor antagonists like ranitidine may cause diarrhea, dizziness, and headaches.Aspirin: Contraindications
Aspirin should be avoided in patients with a history of hypersensitivity to NSAIDs or gastritis/peptic ulcer disease due to the increased risk of gastrointestinal bleeding. -
This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 49
Correct
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Methimazole (MMI) has a modest therapeutic advantage over carbimazole in the treatment of thyrotoxicosis.
Which of the following properties causes this?
Select the SINGLE property from the list below.Your Answer: Inhibits T4 to T3 conversion
Explanation:Comparison of PTU and Carbimazole in the Treatment of Hyperthyroidism
PTU and carbimazole are two commonly used medications in the treatment of hyperthyroidism. While both drugs are effective in reducing thyroid hormone levels, there are some differences in their mechanisms of action and adverse effects.
One advantage of PTU over carbimazole is its ability to inhibit the conversion of T4 to the more active form T3. This is due to its inhibition of the enzyme 5′-deiodinase. However, both drugs inhibit the organification of iodine at the thyroid gland by inhibiting the enzyme thyroperoxidase.
While both drugs are present in breast milk, the amount is likely too small to affect the infant. However, high doses may impact neonatal thyroid function, so monitoring is necessary.
Carbimazole is considered to be at least 10 times as potent as PTU. Additionally, the two drugs have different chemical structures and therefore have slightly different adverse effects profiles. Common side effects include rash, hair loss, and skin pigmentation, while rare but serious side effects include aplastic anaemia, agranulocytosis, and fulminant liver failure.
Patients taking either medication should be aware of the signs of liver disease and seek medical attention if they experience symptoms such as anorexia, nausea, vomiting, fatigue, abdominal pain, jaundice, dark urine, or pruritus. Regular liver function monitoring is also recommended.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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Question 50
Correct
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A 30-year-old farmer with a history of depression arrives at the emergency department complaining of blurred vision, runny nose, watery eyes, diarrhoea, and vomiting. The patient admits to ingesting a pesticide in an attempt to commit suicide. What other clinical manifestations should be anticipated in this individual?
Your Answer: Bradycardia
Explanation:This individual is displaying symptoms consistent with organophosphate poisoning, which is a type of pesticide. Organophosphate pesticides work by inhibiting acetylcholinesterase, which affects the nervous system. This causes an accumulation of acetylcholine at nerve synapses and neuromuscular junctions, resulting in excessive stimulation of muscarinic and nicotinic receptors. As a result, bradycardia is a common symptom. The recommended treatment for organophosphate poisoning is atropine, which should be administered every 10-20 minutes until secretions dry up and the heart rate increases to 80-90 beats per minute.
The options of dilated pupils, dry mouth, and hallucinations are incorrect. Organophosphate poisoning typically causes miosis (constricted pupils) due to overstimulation of the parasympathetic system, excessive secretions including salivation, bronchial secretions, diarrhea, and vomiting. While confusion, agitation, and coma may occur in severe cases, hallucinations are not a common symptom.
Understanding Organophosphate Insecticide Poisoning
Organophosphate insecticide poisoning is a condition that occurs when there is an accumulation of acetylcholine in the body, leading to the inhibition of acetylcholinesterase. This, in turn, causes an upregulation of nicotinic and muscarinic cholinergic neurotransmission. In warfare, sarin gas is a highly toxic synthetic organophosphorus compound that has similar effects. The symptoms of organophosphate poisoning can be remembered using the mnemonic SLUD, which stands for salivation, lacrimation, urination, and defecation/diarrhea. Other symptoms include hypotension, bradycardia, small pupils, and muscle fasciculation.
The management of organophosphate poisoning involves the use of atropine, which helps to counteract the effects of acetylcholine. However, the role of pralidoxime in the treatment of this condition is still unclear. Meta-analyses conducted to date have failed to show any clear benefit of pralidoxime in the management of organophosphate poisoning.
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This question is part of the following fields:
- Pharmacology/Therapeutics
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