The fate of [14C]trithiozine in man

Abstract

1. Radioactivity of [¹⁴C]trithiozine (4-(3,4,5-trimethoxythiobenzoyl)tetrahydro-1,4-oxazine) was recovered quantitatively in the excreta within four days of a single dose (400 mg) given to four human subjects. The urine was the major route of elimination. 2. The concn. of parent drug in plasma showed a peak at 1.5 h after dosing and a half-life 7h. Two metabolites were detected in plasma, corresponding to the products of desulphuration and demethylation. 3. Little unchanged drug was excreted in urine (0.9%). Major pathways of metabolism were O-demethylation at the 3 or 4 positions of the benzene ring followed by conjugation, S-oxidation to the sulphoxide, and desulphuration of the thiobenzoyl group to form the benzoyl analogue. The trimethoxybenzoyl metabolite underwent O-demethylation at the 3 or 4 position of the benzene ring following by conjugation, mono- and di-hydroxylation of the heterocyclic ring and scission of the heterocyclic ring to yield both neutral and acid metabolites.