Anticipatory nausea and vomiting associated with chemotherapy occurs:

Correct Answer: C

Rationale: Anticipatory nausea and vomiting occur before chemotherapy administration and are a conditioned response to previous chemotherapy experiences. This psychological response is triggered by cues such as the sight or smell of the treatment environment. It is distinct from acute or delayed nausea and vomiting, which occur during or after chemotherapy. Anticipatory nausea and vomiting can be challenging to manage and often require behavioral interventions or anti-anxiety medications.

Correct Answer: D

Rationale: Acute asthma and pneumonia in pregnancy require urgent care. IV crystalloids rehydrate, safe and necessary. High FiO2 (40%) supports oxygenation in asthma/pneumonia, appropriate. Nebulized salbutamol, a beta-agonist, relieves bronchospasm, standard and safe. IV hydrocortisone reduces inflammation, suitable. IV gentamicin, an aminoglycoside, treats pneumonia but is inappropriate due to cephalosporin cross-reactivity risk (angioedema history) and fetal ototoxicity concerns, making it unsafe here. Alternative antibiotics (e.g., macrolides) are preferred, prioritizing maternal and fetal safety.

Correct Answer: C

Rationale: All calcium channel blockers (CCBs) like verapamil and nifedipine are orally active, so that's false. Half-lives vary (e.g., nifedipine ~2-5 hours, diltiazem longer), not uniformly 8-12 hours, making that false. They block L-type voltage-gated calcium channels, reducing vascular and cardiac contractility, a true statement. They relax bronchiolar smooth muscle, not unaffected, so that's false. Dihydropyridines cause reflex tachycardia, not bradycardia. The L-type blockade is their unifying mechanism, key to antihypertensive and antianginal effects.

Correct Answer: D

Rationale: Androgen therapy, typically testosterone, aims to increase libido and treat erectile dysfunction in men with hypogonadism, restoring sexual drive. Decreasing libido opposes its intent. It doesn't release FSH or increase LH-exogenous testosterone suppresses these via feedback. Boosting libido corrects deficiency symptoms, improving quality of life, a primary clinical goal.

Correct Answer: C

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.