Which of the following analgesic agents poses a risk in a 60 -year-old patient with a history of transient ischemic attacks

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: Amoxicillin is effective against many strains of Haemophilus influenzae (B), making it a first-line choice for infections like otitis media and pneumonia caused by this pathogen. Unlike benzylpenicillin, it has a broader spectrum, but it is susceptible to beta-lactamases (A), contrary to the statement, unless combined with clavulanic acid (as in co-amoxiclav). It's effective in many community-acquired urinary tract infections (C) caused by Escherichia coli, so that option is incorrect. Drug-related skin rashes can appear after dosing stops (D), especially in delayed hypersensitivity, and are more common in infectious mononucleosis (original E), but B is the key correct statement. Amoxicillin's efficacy against H. influenzae relies on its beta-lactam structure inhibiting cell wall synthesis, though resistance from beta-lactamase production necessitates combination therapies in some cases.

Correct Answer: B

Rationale: Tetracyclines are used to treat Lyme disease (B), caused by Borrelia burgdorferi, with doxycycline as a first-line oral therapy due to its efficacy against spirochetes and good tissue penetration. They're ineffective against Clostridium difficile (A), where metronidazole or vancomycin is preferred, and may exacerbate colitis. They treat acne vulgaris (C) by reducing Propionibacterium acnes and inflammation, often with topical or systemic forms. They're not used for systemic lupus erythematosus (D), an autoimmune condition managed with immunosuppressants. Non-specific urethritis (original E) responds to tetracyclines like doxycycline for Chlamydia. Their bacteriostatic action on protein synthesis and broad-spectrum coverage make tetracyclines versatile, though photosensitivity and tooth discoloration limit use in certain populations.

Correct Answer: B

Rationale: Dapsone is indicated in multibacillary leprosy (B), a cornerstone of multidrug therapy with rifampicin and clofazimine, targeting Mycobacterium leprae effectively due to its bacteriostatic action on folate synthesis. It's not used for amoebiasis (A), where metronidazole is preferred. It treats dermatitis herpetiformis (C), a gluten-sensitive skin condition, reducing inflammation. It's acetylated in the liver (D), with fast/slow acetylator status affecting its metabolism. It has cross-sensitivity with sulfonamides (original E), relevant for allergy screening. Dapsone's utility in leprosy leverages its long half-life and synergy with other drugs, though hemolysis (especially in G6PD deficiency) and methemoglobinemia are key adverse effects requiring monitoring.