Tiagabine is rapidly and almost completely absorbed, with peak concentrations achieved in 30 to 90 minutes. Tiagabine is 96% bound to albumin and alpha glycoprotein and is extensively metabolized by the hepatic CYP3A4 isoenzyme.39

Effect of liver disease

The pharmacokinetics of tiagabine were compared in four subjects with mild liver impairment, three subjects with moderate liver impairment, and matched controls. The Cmax, Cmin, AUC, and elimination half-lives were all higher in the patients with liver impairment. The free fractions were also increased in the hepatically impaired subjects. The recommendation is that the dose, dosing interval, or both be reduced when tiagabine is given to patients with liver impairment.40

Effect of GI disease

The effect of GI disease on the pharmacokinetics of tiagabine is unknown.

Adapted from: Garnett WR. Gastrointestinal and hepatic disease. In: Ettinger AB and Devinsky O, eds. Managing epilepsy and co-existing disorders. Boston: Butterworth-Heinemann; 2002;63-74. 
With permission from Elsevier ( 

Reviewed By: 
Steven C. Schachter, MD
Monday, March 1, 2004