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.

Gastroenteritis can occur either at home or while traveling, known as travelers’ diarrhea. This condition is characterized by at least three loose to watery stools in 24 hours, accompanied by abdominal cramps, fever, nausea, vomiting, or blood in the stool. The most common cause of travelers’ diarrhea is Escherichia coli. Acute food poisoning is another pattern of illness that results in sudden onset of nausea, vomiting, and diarrhea after ingesting a toxin. Staphylococcus aureus, Bacillus cereus, or Clostridium perfringens are typically responsible for acute food poisoning.

There are several types of infections that can cause gastroenteritis, each with its own typical presentation. Escherichia coli is common among travelers and causes watery stools, abdominal cramps, and nausea. Giardiasis results in prolonged, non-bloody diarrhea, while cholera causes profuse, watery diarrhea and severe dehydration leading to weight loss. Shigella causes bloody diarrhea, vomiting, and abdominal pain, while Staphylococcus aureus results in severe vomiting with a short incubation period. Campylobacter typically starts with a flu-like prodrome and progresses to crampy abdominal pains, fever, and diarrhea, which may be bloody and mimic appendicitis. Bacillus cereus can cause two types of illness, vomiting within six hours, typically due to rice, or diarrheal illness occurring after six hours. Amoebiasis has a gradual onset of bloody diarrhea, abdominal pain, and tenderness that may last for several weeks.

The incubation period for gastroenteritis varies depending on the type of infection. Staphylococcus aureus and Bacillus cereus have an incubation period of 1-6 hours, while Salmonella and Escherichia coli have an incubation period of 12-48 hours. Shigella and Campylobacter have an incubation period of 48-72 hours, while Giardiasis and Amoebiasis have an incubation period of more than seven days.

The neonate is diagnosed with congenital rubella syndrome, which is characterized by sensorineural deafness, eye abnormalities, and congenital heart disease. The risk of fetal infection is highest if the mother contracts the virus during the first trimester of pregnancy. Antenatal cytomegalovirus infection can lead to cerebral calcification, microcephaly, and sensorineural deafness. HIV does not pose a physical risk to the developing fetus, but there is a risk of perinatal transmission. Parvovirus B19 can cause hydrops fetalis and fetal death. Toxoplasmosis can result in intracranial calcification, hydrocephalus, and epilepsy in the affected child.

Rubella and Pregnancy: Risks, Features, Diagnosis, and Management

Rubella, also known as German measles, is a viral infection caused by the togavirus. Thanks to the introduction of the MMR vaccine, it is now rare. However, if contracted during pregnancy, there is a risk of congenital rubella syndrome, which can cause serious harm to the fetus. It is important to note that the incubation period is 14-21 days, and individuals are infectious from 7 days before symptoms appear to 4 days after the onset of the rash.

The risk of damage to the fetus is highest in the first 8-10 weeks of pregnancy, with a risk as high as 90%. However, damage is rare after 16 weeks. Features of congenital rubella syndrome include sensorineural deafness, congenital cataracts, congenital heart disease (e.g. patent ductus arteriosus), growth retardation, hepatosplenomegaly, purpuric skin lesions, ‘salt and pepper’ chorioretinitis, microphthalmia, and cerebral palsy.

If a suspected case of rubella in pregnancy arises, it should be discussed immediately with the local Health Protection Unit (HPU) as type/timing of investigations may vary. IgM antibodies are raised in women recently exposed to the virus. It should be noted that it is very difficult to distinguish rubella from parvovirus B19 clinically. Therefore, it is important to also check parvovirus B19 serology as there is a 30% risk of transplacental infection, with a 5-10% risk of fetal loss.

If a woman is tested at any point and no immunity is demonstrated, they should be advised to keep away from people who might have rubella. Non-immune mothers should be offered the MMR vaccination in the post-natal period. However, MMR vaccines should not be administered to women known to be pregnant or attempting to become pregnant.

Treatment options for stroke prevention in atrial fibrillation patients: Understanding CHADS-VASc score

Atrial fibrillation (AF) patients with a CHADS-VASc score of 3 or higher require treatment with either warfarin or a novel oral anticoagulant (NOAC) to prevent stroke. Aspirin, clopidogrel, low-molecular-weight heparin, and strict dietary modification are not recommended for stroke prevention in AF patients.

The CHADS-VASc score is used to calculate the risk of stroke in AF patients. The score includes factors such as congestive cardiac failure, hypertension, age, diabetes mellitus, previous stroke or transient ischaemic attack, vascular disease, and sex category. Men with a score of 2 or higher are considered to be at high risk of stroke and should start treatment with warfarin or a NOAC. Men with a score of 1 are considered to be at moderate risk and should consider anticoagulation. Women aged <65 years with no other risk factors are considered to be at low risk and do not require anticoagulation. Clopidogrel is an oral antiplatelet agent used in the prevention of atherosclerotic events in patients with coronary artery disease, peripheral arterial disease, and cerebrovascular disease. It is not recommended for stroke prevention in AF patients. Strict dietary modification is not an appropriate treatment for AF and essential hypertension. Low molecular weight heparins (LMWHs) are not used in the management of AF. They are commonly used in the prevention and treatment of venous thromboembolism, unstable angina, and acute myocardial infarction.

The patient in question is likely suffering from glandular fever, a viral illness caused by the Ebstein-Barr virus. Symptoms include a sore throat, fever, and general malaise, as well as palpable cervical lymphadenopathy and an erythematous throat. The illness is more common in teenagers and is often spread through respiratory droplets, earning it the nickname kissing disease. The patient was prescribed amoxicillin by their GP, which can cause a non-specific maculopapular rash in patients with glandular fever. The diagnosis is typically confirmed through a Monospot blood test, which detects the presence of heterophil antibodies produced in response to the virus.

An anti-streptolysin O titre test can detect streptococcal infections, but it does not explain the patient’s rash following antibiotic use. A full blood count can be helpful in diagnosing glandular fever, as it often shows a lymphocytosis, but the Monospot test is more definitive. A nasopharyngeal aspirate for viral PCR can diagnose viral infections like measles, but this is less likely in a teenager in the UK due to vaccination. A sputum culture is not useful in diagnosing glandular fever, as the patient does not have a cough or sputum production.

Understanding Infectious Mononucleosis

Infectious mononucleosis, also known as glandular fever, is a viral infection caused by the Epstein-Barr virus (EBV) in 90% of cases. It is most commonly seen in adolescents and young adults. The classic triad of symptoms includes sore throat, pyrexia, and lymphadenopathy, which are present in around 98% of patients. Other symptoms include malaise, anorexia, headache, palatal petechiae, splenomegaly, hepatitis, lymphocytosis, haemolytic anaemia, and a maculopapular rash. The symptoms typically resolve after 2-4 weeks.

The diagnosis of infectious mononucleosis is confirmed through a heterophil antibody test (Monospot test) in the second week of the illness. Management is supportive and includes rest, drinking plenty of fluids, avoiding alcohol, and taking simple analgesia for any aches or pains. It is recommended to avoid playing contact sports for 4 weeks after having glandular fever to reduce the risk of splenic rupture.

Interestingly, there is a correlation between EBV and socioeconomic groups. Lower socioeconomic groups have high rates of EBV seropositivity, having frequently acquired EBV in early childhood when the primary infection is often subclinical. However, higher socioeconomic groups show a higher incidence of infectious mononucleosis, as acquiring EBV in adolescence or early adulthood results in symptomatic disease.

Acute mesenteric ischaemia (AMI) is a rare but potentially life-threatening condition caused by inadequate blood flow through the mesenteric vessels, leading to ischaemia and gangrene of the bowel wall. It can be classified as either arterial or venous, with embolic phenomena being the most common cause. Symptoms include sudden and severe abdominal pain, vomiting, and diarrhoea, with physical signs developing late in the disease process. Early and aggressive diagnosis and treatment are crucial to reduce mortality, but once bowel wall infarction has occurred, the mortality rate may be as high as 90%. Appendicitis, diverticulitis, pseudomembranous colitis, and ruptured AAA are important differential diagnoses to consider.

Cardiomyopathy can be caused by anthracyclines such as doxorubicin.

Cytotoxic agents are drugs that are used to kill cancer cells. There are several types of cytotoxic agents, each with their own mechanism of action and adverse effects. Alkylating agents, such as cyclophosphamide, work by causing cross-linking in DNA. However, they can also cause haemorrhagic cystitis, myelosuppression, and transitional cell carcinoma. Cytotoxic antibiotics, like bleomycin, degrade preformed DNA and can lead to lung fibrosis. Anthracyclines, such as doxorubicin, stabilize the DNA-topoisomerase II complex and inhibit DNA and RNA synthesis, but can also cause cardiomyopathy. Antimetabolites, like methotrexate, inhibit dihydrofolate reductase and thymidylate synthesis, leading to myelosuppression, mucositis, liver fibrosis, and lung fibrosis. Fluorouracil (5-FU) is a pyrimidine analogue that induces cell cycle arrest and apoptosis by blocking thymidylate synthase, but can also cause myelosuppression, mucositis, and dermatitis. Cytarabine is a pyrimidine antagonist that interferes with DNA synthesis specifically at the S-phase of the cell cycle and inhibits DNA polymerase, but can also cause myelosuppression and ataxia. Drugs that act on microtubules, like vincristine and vinblastine, inhibit the formation of microtubules and can cause peripheral neuropathy, paralytic ileus, and myelosuppression. Docetaxel prevents microtubule depolymerisation and disassembly, decreasing free tubulin, but can also cause neutropaenia. Topoisomerase inhibitors, like irinotecan, inhibit topoisomerase I which prevents relaxation of supercoiled DNA, but can also cause myelosuppression. Other cytotoxic drugs, such as cisplatin, cause cross-linking in DNA and can lead to ototoxicity, peripheral neuropathy, and hypomagnesaemia. Hydroxyurea (hydroxycarbamide) inhibits ribonucleotide reductase, decreasing DNA synthesis, but can also cause myelosuppression.

The tricuspid valve is the valve most commonly affected by infective endocarditis in intravenous drug users.

Aetiology of Infective Endocarditis

Infective endocarditis is a condition that affects patients with previously normal valves, rheumatic valve disease, prosthetic valves, congenital heart defects, intravenous drug users, and those who have recently undergone piercings. The strongest risk factor for developing infective endocarditis is a previous episode of the condition. The mitral valve is the most commonly affected valve.

The most common cause of infective endocarditis is Staphylococcus aureus, particularly in acute presentations and intravenous drug users. Historically, Streptococcus viridans was the most common cause, but this is no longer the case except in developing countries. Streptococcus mitis and Streptococcus sanguinis are the two most notable viridans streptococci, commonly found in the mouth and dental plaque. Coagulase-negative Staphylococci such as Staphylococcus epidermidis are the most common cause of endocarditis in patients following prosthetic valve surgery.

Streptococcus bovis is associated with colorectal cancer, with the subtype Streptococcus gallolyticus being most linked to the condition. Non-infective causes of endocarditis include systemic lupus erythematosus and malignancy. Culture negative causes may be due to prior antibiotic therapy or infections caused by Coxiella burnetii, Bartonella, Brucella, or HACEK organisms (Haemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella).

If hydrogen peroxide is not appropriate, topical fusidic acid can be used for impetigo.

Understanding Impetigo: Causes, Symptoms, and Management

Impetigo is a common bacterial skin infection that affects both children and adults. It is caused by either Staphylococcus aureus or Streptococcus pyogenes and can develop anywhere on the body, but lesions tend to occur on the face, flexures, and limbs not covered by clothing. The infection can be a primary infection or a complication of an existing skin condition such as eczema, scabies, or insect bites. Impetigo is highly contagious and can spread through direct contact with discharges from the scabs of an infected person or indirectly through toys, clothing, equipment, and the environment.

The symptoms of impetigo include ‘golden’, crusted skin lesions typically found around the mouth. The infection can be managed with limited, localized disease by using hydrogen peroxide 1% cream or topical antibiotic creams such as fusidic acid or mupirocin. However, if the disease is extensive, oral flucloxacillin or oral erythromycin may be prescribed. It is important to note that MRSA is not susceptible to either fusidic acid or retapamulin, so topical mupirocin should be used in this situation.

Children with impetigo should be excluded from school until the lesions are crusted and healed or 48 hours after commencing antibiotic treatment. It is also important to practice good hygiene, such as washing hands regularly and avoiding close contact with infected individuals, to prevent the spread of impetigo. By understanding the causes, symptoms, and management of impetigo, individuals can take steps to prevent and treat this common bacterial skin infection.

The recommended treatment for acute pulmonary oedema in this patient is IV loop diuretic, specifically furosemide. This is because the patient is experiencing acute decompensated heart failure, which causes pulmonary oedema. IV loop diuretic has a prompt diuretic effect, reducing ventricular filling pressures and improving symptoms within 30 minutes.

IV dobutamine is not necessary for this patient as they are not in shock and dobutamine is typically reserved for patients with severe left ventricular dysfunction who have potentially reversible cardiogenic shock.

IV morphine is not recommended for acute heart failure as it may increase morbidity in patients with acute pulmonary oedema.

Oral furosemide is not the preferred route of administration for this patient as IV furosemide has a faster onset of diuresis.

Heart failure requires acute management, with recommended treatments for all patients including IV loop diuretics such as furosemide or bumetanide. Oxygen may also be necessary, with guidelines suggesting oxygen saturations be kept at 94-98%. Vasodilators such as nitrates should not be routinely given to all patients, but may have a role in cases of concomitant myocardial ischaemia, severe hypertension, or regurgitant aortic or mitral valve disease. However, hypotension is a major side-effect/contraindication. Patients with respiratory failure may require CPAP, while those with hypotension or cardiogenic shock may require inotropic agents like dobutamine or vasopressor agents like norepinephrine. Mechanical circulatory assistance such as intra-aortic balloon counterpulsation or ventricular assist devices may also be necessary. Regular medication for heart failure should be continued, with beta-blockers only stopped in certain circumstances. Opiates should not be routinely offered to patients with acute heart failure due to potential increased morbidity.

In summary, acute management of heart failure involves a range of treatments depending on the patient’s specific condition. It is important to carefully consider the potential side-effects and contraindications of each treatment, and to continue regular medication for heart failure where appropriate. Opiates should be used with caution, and only in cases where they are likely to reduce dyspnoea/distress without causing harm. With appropriate management, patients with acute heart failure can receive the care they need to improve their outcomes and quality of life.