This drug is a potassium channel activator:

Correct Answer: C

Rationale: Step-by-step rationale: 1. Diazoxide is a potassium channel activator that works by opening ATP-sensitive potassium channels in smooth muscle cells. 2. This action leads to hyperpolarization of the cell membrane, resulting in relaxation of vascular smooth muscle. 3. This vasodilatory effect is beneficial in conditions like hypertension and hypoglycemia. 4. Nifedipine (A) is a calcium channel blocker, Saralasin (B) is an angiotensin II receptor antagonist, and Losartan (D) is an angiotensin II receptor blocker. Summary: - Nifedipine does not activate potassium channels. - Saralasin and Losartan do not have a direct effect on potassium channels. - Diazoxide is the correct choice as it specifically activates potassium channels to induce vasodilation.

Correct Answer: C

Rationale: The correct answer is C: Biguanides. Biguanides, such as metformin, potentiate the action of insulin by improving insulin sensitivity in tissues, reducing hepatic glucose production, and enhancing peripheral glucose uptake. Sulphonylureas (A) stimulate insulin secretion, glucagon (B) increases blood glucose levels, and D is incorrect as biguanides do potentiate insulin action.

Correct Answer: C

Rationale: The correct answer is C (Antipyretic, analgesic, anti-inflammatory) for NSAIDs. NSAIDs primarily work by inhibiting COX enzymes, reducing inflammation, pain, and fever. A is incorrect because not all NSAIDs have antihistaminic properties. B is incorrect because NSAIDs are not typically immunodepressive. D is incorrect because antihistaminic properties are not common in NSAIDs. In summary, the unique combination of antipyretic, analgesic, and anti-inflammatory properties is peculiar to the majority of NSAIDs.

Correct Answer: D

Rationale: The correct answer is D: Idiopathic nephrotic syndrome. Cyclosporine A is indicated for the treatment of idiopathic nephrotic syndrome due to its immunosuppressive properties that help reduce proteinuria and preserve renal function. In contrast, choices A, B, and C are incorrect because cyclosporine A is not typically used for secondary immunodeficiency, hairy cell leukemia, or primary immunodeficiency. These conditions require different treatment approaches not involving cyclosporine A.

Correct Answer: A

Rationale: The correct answer is A. Pellagra is caused by a deficiency of niacin, leading to symptoms like skin eruptions, digestive and nervous system disturbances, and mental deterioration. Choice B refers to beriberi, caused by thiamin deficiency. Option C describes pernicious anemia, caused by a lack of vitamin B12. Option D is incorrect as it includes all the above conditions, which is not the case. Overall, the key points to remember are the specific symptoms of pellagra and the deficiency of niacin as the cause.