The effects of an oral enteric-coated preparation (VAL 579 capsules) of sodium valproate (VPA) were compared with those of conventional oral and rectal preparations in 24 epileptic patients. Enteric-coated capsules are useful for avoiding gastric intolerance to VPA. Plasma VPA level peaks after the enteric- coated form were later than after other forms. The bioavailability appeared to be the same for all the forms.