Metabolism of fentiazac.

The main metabolite of 2-phenyl-4-p-chlorophenylthiazol-5-ylacetic acid (fentiazac) is represented by a p-hydroxylated compound which is formed rapidly and that, still 72 later, can be detected in the general circulation. The p-hydroxylated metabolite is much less toxic than the original molecule from which it derives, being still active from an anti-inflammatory standpoint (its activity being equal to 70--75% of that of fentiazac). The metabolite, which possesses a therapeutic index much higher than that of fentiazac, represents quite an important step in the detoxication processes of the drug and enhances the therapeutic activity of the drug itself.