Major
Established
설명
The combination of topiramate and valproic acid is associated with hyperammonemia and encephalopathy even without hepatotoxicity, representing a unique metabolic interaction.
기전
Both drugs inhibit carbonic anhydrase and disrupt the urea cycle; topiramate inhibits carbamoyl phosphate synthetase I, and valproate impairs mitochondrial metabolism, resulting in ammonia accumulation.
임상적 중요성
Hyperammonemic encephalopathy can occur without elevated liver enzymes or serum valproate toxicity; the condition is reversible upon drug discontinuation.
관리 방법
Monitor ammonia levels if altered mental status develops; reduce or discontinue topiramate if hyperammonemia is confirmed.