These drug - adverse effect pairs are incorrect except

• A. Verapamil - Diarrhea
• B. Atypical antipsychotics - Weight gain
• C. Celecoxib - GI toxicity
• D. Biphosphonates - Hyperphosphatemia

Answer: (B)

When evaluating drug-adverse effect pairs, the best match is the one that reflects a well-known and common side effect for that drug class. Atypical antipsychotics are famously associated with weight gain due to their metabolic effects, appetite changes, and insulin sensitivity impact, so weight gain is a credible, frequent adverse effect for this class.

Verapamil tends to cause constipation rather than diarrhea, since calcium channel blockers slow gut motility. That makes diarrhea an unlikely common pairing. Celecoxib does carry GI risk, but COX-2 inhibitors generally have lower GI toxicity than nonselective NSAIDs, so labeling GI toxicity as the characteristic adverse effect overstates its typical risk. Biphosphonates commonly cause esophagitis, dyspepsia, and can lead to hypocalcemia, not hyperphosphatemia.

So the strongest, correct association is weight gain with atypical antipsychotics.