Valproic Acid Overdose and l-Carnitine Therapy

Abstract

A healthy, nonepileptic 16-month-old child ingested a massive overdose (approximately 4000 rag) of valproic acid (VPA). Upon admission to the hospital, he was in a deep coma and had generalized hypotonicity and no response to pain. His serum and urinary concentrations of VPA were 1316.2 and 3289.5 pg/mL, respectively. Urinary concentrations of the ~-oxidation metabolites of VPA were low, whereas concentrations of (0-and (01-oxidation metabolites were high. Moreover, 4-en-valproate (a potential hepatotoxin) was detected in the urine. Gastric lavage and general supportive measures were undertaken, including intravenous infusion to increase urine output and oral t-carnitine to correct hypocarnitinemia. Subsequently, the ~-oxidation metabolites increased, the co-and (01-oxidation metabolites decreased, and 4en-valproate was no longer detected. The patient recovered completely and was discharged on the eighth hospital day without any sequelae. This case suggests that enhanced drug excretion and t-carnitine supplementation may prevent potentially fatal hepatic dysfunction after VPA overdose.