Teratogenesis of sodium valproate

Abstract

Sodium valproate has been a first-line antiepileptic drug for 40 years. A recent multicentre study conducted in the UK (Standard and New Antiepileptic Drugs) has confirmed what most practising neurologists had long suspected – that sodium valproate is the most effective drug in the treatment of idiopathic generalized epilepsy and juvenile myoclonic epilepsy. Knowledge of the drug's unsurpassed efficacy has intensified the dilemma faced by neurologists treating people with epilepsy, and in particular young women. Recent data from pregnancy registers has not only confirmed that sodium valproate is teratogenic but also that it may be associated with neurodevelopmental delay and autistic spectrum disorders in the children of women exposed to the drug during pregnancy. Thus physicians have to balance the undoubted benefits of seizure freedom for their female patients with the potential long-term consequences for the infants of these patients. There is undoubtedly a phamacogenetic component to sodium valproate's teratogenic and neurodevelopmental effects. Future research may enable us to identify those women whose offspring may be affected. Research now underway will help quantify the precise risk of neurodevelopmental delay in the offspring of women exposed to the drug, although it will be some years before results become available.