Mild acne may be initially treated with:

Correct Answer: A

Rationale: The correct answer is A: OTC benzoyl peroxide. Initially treating mild acne with OTC benzoyl peroxide is effective as it helps to kill acne-causing bacteria, reduce inflammation, and unclog pores. It is a common first-line treatment for mild acne due to its efficacy and accessibility. Minocycline (B) is an oral antibiotic usually reserved for moderate to severe acne. Topical combined antibiotic (C) and topical retinoid (D) are also effective treatments, but typically prescribed for more moderate to severe cases of acne. Benzoyl peroxide is a safe and cost-effective option for mild acne, making it the best choice for initial treatment.

Correct Answer: C

Rationale: The correct answer is C: Biguanide (metformin). Metformin decreases hepatic glucose production by inhibiting gluconeogenesis and increases insulin sensitivity in peripheral tissues, which enhances glucose uptake. Sulfonylureas and meglitinides stimulate insulin secretion from the pancreas. Alpha-glycosidase inhibitors delay carbohydrate absorption in the gut. Metformin's dual mechanism of action makes it the correct choice for decreasing hepatic glucose production and increasing insulin sensitivity and peripheral glucose uptake.

Correct Answer: A

Rationale: The correct answer is A (TRUE). Metoclopramide (Reglan) does carry a black box warning due to the risk of tardive dyskinesia with long-term use. Tardive dyskinesia is characterized by involuntary movements of the face and body and can be irreversible. The warning emphasizes the importance of using metoclopramide for the shortest duration possible to minimize this risk. The other choices (B, C, D) are incorrect because the black box warning for tardive dyskinesia associated with metoclopramide is a well-documented fact supported by clinical evidence and regulatory agencies.

Correct Answer: D

Rationale: The correct answer is D because NSAIDs inhibit prostaglandin synthesis. Prostaglandins are lipid compounds that promote inflammation, pain, and fever. By inhibiting their synthesis, NSAIDs reduce inflammation and pain. Choice A is incorrect as the chemoreceptor trigger zone is not related to the anti-inflammatory effect of NSAIDs. Choice B is also incorrect as NSAIDs do not reset the hypothalamic 'setpoint'. Choice C is incorrect as the correct answer is D.

Correct Answer: C

Rationale: The correct answer is C: NMDA receptor antagonist. Memantine is an NMDA receptor antagonist, which means it blocks the activity of NMDA receptors, specifically by binding to the receptor-operated cation channels and blocking the excessive influx of calcium ions. This mechanism helps regulate glutamate activity and prevents excitotoxicity. Choices A and B are incorrect because memantine is not related to GABA function or concentration. Choice D is incorrect as an NMDA receptor agonist would increase receptor activity, opposite to memantine's action.