Ticlopidine is an inhibitor of ADP-induced platelet aggregation. It’s:

Correct Answer: A

Rationale: Step-by-step rationale: 1. Ticlopidine is a thienopyridine derivative that inhibits ADP-induced platelet aggregation. 2. By inhibiting the binding of ADP to its platelet receptor, it prevents platelet activation and aggregation. 3. This mechanism of action makes ticlopidine an effective antiplatelet medication for preventing clot formation. 4. Therefore, the statement that ticlopidine is an inhibitor of ADP-induced platelet aggregation is TRUE. Summary of other choices: - Choice B (FALSE): This is incorrect as ticlopidine is indeed an inhibitor of ADP-induced platelet aggregation. - Choice C (All): This is incorrect as ticlopidine is not classified as affecting all types of platelet aggregation. - Choice D (None of the above): This is incorrect as the correct answer is A, making this choice invalid.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Nifedipine is a calcium channel blocker that causes vasodilation. 2. Vasodilation leads to a decrease in blood pressure. 3. To compensate, the body may exhibit reflex tachycardia. 4. Therefore, nifedipine routinely produces tachycardia. Summary of incorrect choices: A. Propranolol is a beta-blocker that slows heart rate. B. Clonidine is a centrally-acting alpha-2 agonist that decreases sympathetic outflow, leading to bradycardia. C. Enalapril is an ACE inhibitor that does not directly affect heart rate.

Correct Answer: D

Rationale: The correct answer is D, the mammary gland. Prolactin is a hormone primarily responsible for mammary gland development and milk production in females. It stimulates the mammary alveolar cells to produce milk. The other choices, A: Liver, B: Adrenal cortex, and C: Thyroid, are not directly targeted by prolactin and do not have a primary role in milk production. Therefore, the correct answer is D as it directly correlates with the function of prolactin in the body.

Correct Answer: D

Rationale: The correct answer is D, All of the above. Glucagon, adrenal steroids, and adrenaline are important hormonal antagonists of insulin. Glucagon promotes glucose release from the liver, counteracting insulin's effects. Adrenal steroids and adrenaline increase blood sugar levels by promoting gluconeogenesis and glycogenolysis. Therefore, all these agents act against insulin to regulate blood glucose levels. Other choices are incorrect because each agent individually plays a role in antagonizing insulin's effects.

Correct Answer: C

Rationale: The correct answer is C: Meclofenamic acid. Fenamate derivatives are a specific class of NSAIDs that have a fenamic acid structure. Meclofenamic acid is a fenamate derivative as it contains the fenamic acid structure, making it the correct choice. A: Phenylbutazone is not a fenamate derivative, it belongs to the pyrazolidinedione class. B: Indomethacin is not a fenamate derivative, it belongs to the indoleacetic acid class. D: Diclofenac is not a fenamate derivative, it belongs to the acetic acid class.