Metabolism of carbamazepine.

Thirty-two metabolites of carbamazepine, in addition to the 10,11-epoxide, have been isolated from enzymatically hydrolyzed urine by HPLC and identified by gas-chromatographic and mass-spectrometric techniques. Eight were sulfur-containing methylthio, methylsulfinyl, or methylsulfonyl derivatives. Eighteen new metabolites, including five iminostilbene derivatives that have not been described earlier, were found. All of the metabolites were formed by processes involving epoxidation and a peroxidation, the structures of the metabolites support the hypothesis that multiple epoxides and a cyclic peroxide are involved in the in vivo metabolism of carbamazepine by the rat and man.