Choose an emetic drug of central action:

Correct Answer: D

Rationale: The correct answer is D: Apomorphine hydrochloride. Apomorphine is an emetic drug that acts centrally by stimulating dopamine receptors in the brain, particularly in the chemoreceptor trigger zone. This stimulation triggers the vomiting reflex. A: Ipecacuanha derivatives are peripheral emetics that work by irritating the stomach lining, leading to vomiting. B: Promethazine is an antiemetic drug that works by blocking dopamine receptors and has no emetic properties. C: Tropisetron is a serotonin receptor antagonist used to prevent nausea and vomiting, but it does not induce vomiting itself. In summary, apomorphine hydrochloride is the correct answer as it acts centrally to induce vomiting by stimulating dopamine receptors, whereas the other choices do not have central emetic action.

Correct Answer: D

Rationale: The correct answer is D: Potassium channel openers (Minoxidil). Potassium channel openers do not decrease myocardial oxygen requirement or increase myocardial oxygen delivery in angina. Nitrates and nitrite drugs, calcium channel blockers, and beta-adrenoceptor-blocking drugs all have mechanisms that achieve both of these effects. Nitrates and nitrite drugs dilate coronary arteries, increasing oxygen delivery, and decrease preload, decreasing oxygen demand. Calcium channel blockers reduce myocardial contractility and dilate coronary arteries. Beta-adrenoceptor-blocking drugs reduce heart rate and contractility, thus reducing oxygen demand. Potassium channel openers like minoxidil primarily act as vasodilators but do not have a direct effect on myocardial oxygen demand or delivery in angina.

Correct Answer: B

Rationale: The correct answer is B because diuretics help reduce blood volume and sodium ions, leading to decreased blood pressure. By promoting diuresis, diuretics decrease the workload on the heart and blood vessels, thus helping to manage hypertension. A: Blocking adrenergic transmission is typically done by beta-blockers, not diuretics. C: Depression of the renin-angiotensin-aldosterone system is targeted by ACE inhibitors or angiotensin receptor blockers, not diuretics. D: Depression of the vasomotor center is related to centrally acting antihypertensive medications, not diuretics.

Correct Answer: A

Rationale: The correct answer is A: Vasopressin possesses antidiuretic properties. Vasopressin, also known as antidiuretic hormone (ADH), acts on the kidneys to increase water reabsorption, reducing urine output and conserving water in the body. This helps maintain body fluid balance and prevent dehydration. Choice B is incorrect because vasopressin actually has vasoconstrictive properties, not vasodilatory properties. Choice C is incorrect because vasopressin does not stimulate the release of thyroid hormones. Choice D is also incorrect because vasopressin is known for its antidiuretic effect, not diuretic effect.

Correct Answer: D

Rationale: Step-by-step rationale: 1. Synthetic estrogens are used to treat conditions related to hormonal imbalances. 2. Primary hypogonadism, postmenopausal hormonal therapy, and hormonal contraception are common indications for synthetic estrogens. 3. Simple obesity is not a condition related to hormonal imbalances. 4. Thus, using synthetic estrogens for the treatment of simple obesity is not a valid indication. Summary: A, B, and C are valid indications for synthetic estrogens as they involve hormonal imbalances. D is incorrect as simple obesity does not involve hormonal imbalances.