Two cases of valproic acid poisoning treated with L-carnitine.

Two cases of acute valproic acid poisoning with central nervous system depression and raised ammonia level without hepatotoxicity were reported. They were treated successfully with the use of the antidotes: L-carnitine and other supportive measures. Clinical manifestation and progress was described, and discussion is focused on the use of L-carnitine in valproic acid-induced hyperammonemia, from its mechanism to the clinical experiences in the literature. Based on the favorable response of our two cases and the literature review, we recommend the administration of intravenous L-carnitine in patients of valproic acid overdose with hyperammonemia or valproic acid-induced hyperammonemic encephalopathy and hepatotoxicity at a dose of 50 mg/kg every 8 h for the first initial 24 h with further individual assessment.