Which antiepileptic drug is associated with anorexia and weight loss, symptomatic nephrolithiasis, perioral paraesthesiae, and word-finding difficulties?
- A Zonisamide
- B Gabapentin
- C Topiramate ✓
- D Valproate
Correct answer: C. Topiramate
Explanation
Topiramate blocks AMPA/kainate receptors, enhances GABA activity, and inhibits carbonic anhydrase. Carbonic anhydrase inhibition explains the paraesthesiae and alkaline urine that promotes calcium phosphate stone formation, while its anorectic effect causes weight loss, the opposite of valproate, gabapentin, and pregabalin. Cognitive slowing with word-finding difficulty is characteristic and improves on dose reduction. Zonisamide shares some effects but is classically linked to rash and hypersensitivity.
Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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