Determination of Valproic Acid Concentration in Serum

Gas-chromatographic determination of valproic acid in serum without derivatization.

Valproic acid can be determined by gas-chromatography as the free acid after its extraction (1 ) or derivatization to form methyl, butyl, or phenacyl estars (2-4), the latter methods being more complicated for routine analyses. Other procedures, such as enzyme immunoassay (Syva Co., Palo Alto, CA 94304) or fluoroimmunoassay (Miles Inc., Elkhart, IN 46515), which do not require serum extraction,...

Effect of UGT2B7 genetic variants on serum valproic acid concentration.

OBJECTIVE To investigate the effect of UGT2B7 A268G and UGT2B7 G211T genetic polymorphism on serum drug concentration of valproic acid (VPA). METHODS Genetic polymorphisms of UGT2B7 A268G and UGT2B7 G211T were tested in 248 epileptic patients by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Data including basic information, epilepsy type, times and doses of dr...

Determination of valproic acid in serum by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry.

Square wave voltammetric determination of valproic acid in pharmaceutical Preparations

The electrochemical behavior of valproic acid (VAL) was investigated using square wave voltammetry, cyclic voltammetry, and sampled direct current polarography and a new square wave voltammetric method was developed for determination of VAL in pharmaceutical preparations. VAL showed two reduction peaks at about –0.2 V and –0.8 V vs. Ag/AgCl 3 M KCl with a hanging mercury drop electrode in 0.05 ...

Reduction in serum concentration of valproic acid secondary to the intake of ibuprofen as an example of valproic acid auto-induction metabolism.

INTRODUCTION In 1998, an unexplained drug-drug interaction between valproic acid (VPA) and ibuprofen was reported. VPA has been considered a moderate inhibitor of several metabolic enzymes, but recently its inductive properties have been described, including the possibility of auto-induction. Ibuprofen can displace VPA from the plasmatic protein, increasing its serum free concentration, and sub...