ABSORPTION, ELIMINATION AND METABOLIC-FATE OF BUNAZOSIN IN 3 HEALTHY MALE-VOLUNTEERS

Investigation of the metabolism of C-14-bunazosin (2.0mg) in 3 healthy male volunteers indicated that the primary route of metabolism of thi s alpha1-adrenoceptor antagonist, as for other quinazoline derivatives , is via demethylation and hydroxylation. Of the total radioactivity a dministered, 37% was recovered in the urine and 58% in the faeces over the 7-day period postdose. Urinary radioactivity was accounted for by metabolites (96%). predominantly bunazosin-N-glucuronide and unidenti fied polar compounds, and a small amount of unchanged bunazosin (4%). Faecal radioactivity was due to unchanged bunazosin (11%) and a variet y of metabolites, including 6- and 7-desmethylbunazosin and unidentifi ed polar compounds. O-glucuronides were present in similar amounts in the urine and faeces, whereas N-glucuronides were more abundant in the urine.