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Neurology — PSA MCQ

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HardNeurologyPSA

A 64-year-old man with known epilepsy is admitted for surgery. He has been well-controlled on sodium valproate. According to NICE guidelines, which drug interaction is a key concern when co-prescribing sodium valproate?

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Correct answer: C — Increased risk of toxicity with lamotrigine

Sodium valproate can elevate lamotrigine levels, raising the risk of toxicity (e.g., severe rash such as Stevens-Johnson syndrome). It is not a major inducer of liver enzymes, so the interaction with warfarin is less pronounced than with enzyme-inducing antiepileptics (e.g., phenytoin, carbamazepine). There is no well-known antagonism with digoxin or effect on penicillin absorption or clopidogrel efficacy.

Reference: BNF Antiepileptics