1989 Volume 4 Issue 6 Pages 693-701
The absorption and excretion of 14C-carvedilol were studied in cynomolgus monkeys after an oral administration of 14C-carvedilol at a dose of 10 mg/kg. The distribution of radioactivity was also studied in squirrel monkeys by whole body autoradiography after an oral or intravenous administration of 14C-carvedilol.
Blood level reached to the maximum of about 2.3μg eq./ml at 2h after an oral administration and decreased with the terminal half-life of 31.3h. The concentration of the radioactivity in plasma was higher than that in blood throughout experimental period. It was suggested that the erythrocyte binding in cynomolgus monkeys was clearly low as contrasted with that in rats. After an oral administration of 14C-carvedilol to cynomolgus monkeys, approximately 65% and 16% of dose were excreted within 10 days into feces and urine, respectively.
In the whole body autoradiograms after an oral or intravenous administration to squirrel monkeys, high levels of radioactivity were observed in the gall bladder, liver, intestinal contents. It was suggested that biliary excretion was a major elimination route of carvedilol in monkeys. The distribution of radioactivity to tissues after an oral administration was remarkably low in comparison with that after an intravenous administration.
The accumulation of radioactivity in hair follicles and uveal tract containing melanin were observed in the autoradiograms at 24h after dosing.
