Metabolism and urinary excretion of chlormethiazole in humans.

1. Chlormethiazole and five of its metabolites excreted in urine in man have been investigated by g.l.c.-mass spectrometry. 2. Four metabolites have been identified by comparison with authentic compounds as 5-acetyl-4-methylthiazole, 5-(1-hydroxyethyl)-4-methylthiazole, 5-(2-hydroxyethyl)-4-methylthiazole and 4-methyl-5-thiazoleacetic acid; 4-methyl-5-thiazoleacetaldehyde is proposed for the other metabolite. 3. The amounts of chlormethiazole and its identified metabolites excreted in urine have been quantitatively determined after a single oral dose in three healthy adults. Approximately 16% of the dose was excreted as chlormethiazole, 5-acetyl-4-methylthiazole, 5-(1-hydroxyethyx)-4-methylthiazole and 4-methyl-5-thiazoleacetic acid.