Metabolism of thymoxamine: identification of metabolites in rat.
Thymoxamine hydrochloride administered by mouth to rats at 25 or 100 mg kg-1 was excreted in the urine as the deacetyl and N-demethyl-deacetyl metabolites. These were completely sulpho- and glucuronoconjugated at 25 mg kg-1 but only partially so at the higher dose. Thymoxamine deacetylation in vitro is catalysed by plasma and hepatic cytosol esterases and the deacetyl metabolite undergoes N-demethylation catalysed by the cytochrome P 450 hepatic microsome mixed function monooxygenase system. Because of the rapidity of the deacetylation it is concluded that thymoxamine is a prodrug leading in vivo to the active deacetyl thymoxamine.
D000818:Animals; D001711:Biotransformation; D003600:Cytosol / Q000378:metabolism; D006868:Hydrolysis; D066298:In Vitro Techniques; D008099:Liver / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D013948:Moxisylyte / Q000378:metabolism* / Q000652:urine; D051381:Rats
D013948:Moxisylyte