Which of the following anxiolytics has minimal abuse liability?

Correct Answer: B

Rationale: The correct answer is B: Buspirone. Buspirone is a non-benzodiazepine anxiolytic that has minimal abuse potential, as it does not act on the GABA receptor like benzodiazepines do. Buspirone's mechanism of action involves serotonin and dopamine receptors, making it less likely to be abused compared to benzodiazepines. Rationale: A: Oxazepam is a benzodiazepine, which can lead to dependence and abuse due to its effects on the GABA receptor. C: Flumazenil is a benzodiazepine receptor antagonist used to reverse the effects of benzodiazepine overdose, not an anxiolytic. D: Alprazolam is a benzodiazepine with high abuse potential due to its rapid onset of action and reinforcing effects.

Correct Answer: C

Rationale: Rationale: Cimetidine is an H2 receptor antagonist that can cause reversible gynecomastia by inhibiting androgen receptors. This leads to increased estrogen levels and breast tissue growth in males. Omeprazole (A), Pirenzepine (B), and Sucralfate (D) are not associated with gynecomastia as they do not affect hormone levels in the same way as cimetidine.

Correct Answer: B

Rationale: The correct answer is B: Urokinase. Urokinase is a thrombolytic agent that works by breaking down blood clots, not preventing platelet aggregation like the other options. Aspirin inhibits COX enzyme, Ticlopidine and Clopidogrel are both ADP receptor antagonists which prevent platelet activation. Therefore, urokinase does not belong to the class of antiplatelet agents.

Correct Answer: A

Rationale: The correct answer is A: TRUE. Calcium channel blockers reduce the inward movement of calcium during the action potential in cardiac muscle cells, leading to a decrease in the intracellular calcium concentration. This results in a direct negative inotropic effect by reducing the force of contraction of the heart muscle. Choices B and D are incorrect because calcium channel blockers do indeed have direct negative inotropic effects. Choice C is incorrect as well because not all choices are correct; only choice A is accurate based on the mechanism of action of calcium channel blockers in cardiac muscle cells.

Correct Answer: C

Rationale: Rationale: 1. Losartan is a non-peptide angiotensin II receptor antagonist. 2. Clonidine is a centrally acting alpha-2 adrenergic agonist. 3. Captopril is an ACE inhibitor. 4. Diazoxide is a potassium channel activator, used for hyperinsulinism. Therefore, the correct answer is C, as it specifically targets angiotensin II receptors, unlike the other choices.