Linear Relationship between Plasma Concentration and Dosage of Sodium Valproate

Abstract

Plasma valproate concentration was studied in 7 hospitalized nonepileptic patients who received sodium valproate at daily doses of up to 60 mg/kg. A linear relationship between dose and plasma concentration of valproate (r [correlation coefficient] = 0.81-0.99) was found in each patient, although the slopes of the regression lines (reflecting clearance rates) varied 2-fold. If the valproate plasma concentrations at 2 different doses are known and the clearance of valproate is not altered by concomitant administration of other drugs, it should be possible to predict the plasma valproate concentration that results from further dose increments.