Carnitine, valproate, and toxicity

J Child Neurol. 1991 Jan;6(1):7-14. doi: 10.1177/088307389100600102.


Carnitine is an important nutrient that is present in the diet (particularly in meat and dairy products) and is synthesized from dietary amino acids. It functions to assist long-chain fatty acid metabolism and to regulate the ratio of free coenzyme A to acylcoenzyme A in the mitochondrion. Carnitine deficiency occurs in primary inborn errors of metabolism, in nutritional deficiency, and in various other disorders including antiepileptic drug therapy. Valproate therapy is often associated with decreased carnitine levels and occasionally with true carnitine deficiency. Some experimental and clinical evidence links valproate-induced carnitine deficiency with hepatotoxicity, but this evidence is limited and inconclusive. Carnitine supplementation has been useful in some studies, but these data are also limited. Young children with neurologic disabilities taking multiple antiepileptic drugs may have the greatest risk for carnitine deficiency. Measurement of carnitine levels appears warranted in these patients and in patients with symptoms and signs of possible carnitine deficiency.

Publication types

  • Review

MeSH terms

  • Carnitine / deficiency*
  • Chemical and Drug Induced Liver Injury / enzymology
  • Chemical and Drug Induced Liver Injury / etiology*
  • Chemical and Drug Induced Liver Injury / prevention & control
  • Child
  • Epilepsy / drug therapy*
  • Epilepsy / enzymology
  • Hepatic Encephalopathy / chemically induced*
  • Hepatic Encephalopathy / enzymology
  • Hepatic Encephalopathy / prevention & control
  • Humans
  • Risk Factors
  • Valproic Acid / administration & dosage
  • Valproic Acid / adverse effects*
  • Valproic Acid / pharmacokinetics


  • Valproic Acid
  • Carnitine