A 20-year-old man is diagnosed to have acute schizophrenia. Which of the following is an appropriate first-line treatment?

Correct Answer: C

Rationale: Acute schizophrenia requires antipsychotics for positive symptoms (e.g., hallucinations). IV haloperidol is for acute agitation, not first-line outpatient treatment. IM flupentixol, a long-acting typical antipsychotic, suits maintenance, not initial therapy. Oral olanzapine, an atypical antipsychotic, is first-line, balancing efficacy (D2/5-HT2 blockade) and lower extrapyramidal risk, suitable for a young patient. Procyclidine treats parkinsonism, not schizophrenia. Fluoxetine is for depression. Olanzapine's oral route and profile make it ideal for initial management, promoting adherence and tolerability.

Correct Answer: C

Rationale: Androgens, primarily testosterone, are secreted by the testes' Leydig cells, stimulated by luteinizing hormone (LH) from the pituitary, making the testes the direct source. Follicle-stimulating hormone (FSH) from the pituitary regulates sperm production, not androgen secretion. Gonadotropin-releasing hormone (GnRH) from the hypothalamus triggers pituitary LH and FSH release, indirectly influencing androgen production, not secreting it. The pituitary releases LH and FSH, not androgens itself. The testes' role as the endocrine organ producing androgens is clear, driven by LH, and is fundamental to male reproductive and secondary sexual characteristics, setting it apart from regulatory hormones in the hypothalamic-pituitary-gonadal axis.

Correct Answer: C

Rationale: A P450 enzyme inducer (e.g., rifampin) speeds metabolism of itself and other drugs, reducing its own effect over time as levels drop faster, requiring dose adjustments. No effect on others is extreme-some drugs' metabolism increases, lowering their effect. Increased effects suggest inhibition, not induction. Self-induction lowers efficacy, a pharmacokinetic principle affecting long-term use.

Correct Answer: B

Rationale: Aging reduces liver/renal clearance, raising plasma levels (e.g., digoxin), heightening response and toxicity risk, per pharmacokinetics. Body water drops, concentrating drugs, not diluting. Doses decrease, not increase-metabolism slows. Absorption may slow, but pH rises, not falls. Plasma increase drives effects, key in elders.

Correct Answer: B

Rationale: Calcium absorbs best with food-e.g., fat aids uptake, per pharmacokinetics-unlike empty stomach. Insomnia isn't typical-constipation is. Vitamin D matters-enhances absorption. Meal timing optimizes use, per guidance.