Valproate mitochondrial toxicity — MRCPCH TAS MCQ

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HardPharmacologyValproate mitochondrial toxicityMRCPCH TAS

A 19-month-old with developmental delay starts an antiseizure medicine and develops vomiting, lethargy, raised transaminases and hyperammonaemia. There is a family history of unexplained infant deaths. Which drug is most likely responsible?

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Correct answer: A — Sodium valproate

Valproate can precipitate severe hepatotoxicity and hyperammonaemia, particularly in young children and those with mitochondrial disease such as POLG-related disorders. Levetiracetam is not typically associated with this mitochondrial hepatotoxic pattern. The teaching point is to consider metabolic vulnerability before valproate in infants with developmental delay or suggestive family history.

Reference: BNFc; Nelson Textbook of Pediatrics; RCPCH Theory examination syllabi