Determination of valproic acid serum concentrations and its influencing factors

OBJECTIVE To study the influencing factors of valproic acid (VPA)serum concentration in patients with epilepsy and the relations between VPA serum concentration and clinic effect.METHODS Valproic acid serum concentration of epileptic (CSS)was monitored by gas chromatography,and to evaluate the influence of gender,age,standard dosage(D),dosage form on the specific value of serum concentration and standard dosage(CSS /D),also the relation between combining use of drugs and serum concentration can be analyzed.RESULTS Variance analysis results showed that gender had no siganificant differences(P0.05); there were significant,difference in group of age,standard dosage and dosage form (P0.05). The average serum concentrations of combining carbamazepine was lower than the group taking VPA only;standard dosage was the main influencing factor by regression analysis. CONCLUSION Age,standard dosage,dosage form can effect valproic acid serum concentrations,especially standard dosage but gender,and combining use of drugs also is an influencing factor.