[Is it preferable to prescribe 1 or 2 daily doses of sodium valproate?]

Enteric-coated tablets containing 1 500 mg of sodium valproate (VPA) were administered in a randomized fashion either once or three times a day for 7 days to 6 healthy adult volunteers. Plasma total VPA levels and unbound fractions of the drug were determined 2-hourly on the last day of each treatment. Peak plasma concentrations were higher, and minimum plasma concentrations lower with one single dose than with three doses. In subjects who received three doses, the concentration curves tended to plateau, with higher AUC values. However, none of the differences observed reached statistical significance. The clinical implications of these pharmacokinetic data are discussed.