Pharmacokinetic and Metabolic Investigation of Topiramate Disposition in Healthy Subjects in the Absence and in the Presence of Enzyme Induction by Carbamazepine

Abstract

TPM remains appreciably excreted unchanged in urine (41%) under CBZ-induced conditions, even though TPM CL/F increased by twofold. Although 2,3-diol-TPM and 10-OH-TPM were measured in unconjugated form, the significant increases in their AUC and urinary excretion are consistent with the twofold increase in TPM clearance.