A 24-year-old woman started on an antiepileptic for focal seizures reports tingling in her fingers, weight loss of 4 kg over two months, and difficulty finding words during conversation. She also passes a kidney stone. The offending drug is:
- A Levetiracetam
- B Lamotrigine
- C Topiramate ✓
- D Oxcarbazepine
Correct answer: C. Topiramate
Explanation
Topiramate characteristically causes paresthesias, anorexia with weight loss, word-finding difficulty and cognitive slowing, and carbonic anhydrase inhibition leading to metabolic acidosis and calcium phosphate nephrolithiasis. Levetiracetam can cause behavioural changes but not stones or weight loss, lamotrigine's key hazard is rash, and oxcarbazepine is associated with hyponatremia rather than this cluster.
Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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