Metabolism, plasma or serum levels, and elimination of phenformin in guinea pigs, rats, and dogs.
14C-Phenformin hydrochloride was used for investigating the metabolism, plasma or serum levels, and elimination of the drug following 1.5-mg/kg po or iv doses to guinea pigs, rats, and dogs. The amounts of individual metabolites and unchanged drug were assessed in urine as well as in plasma or serum. The glucuronide of 1-(p-hydroxyphenethyl)biguanide was a major metabolite in the blood and urine of all three species. Guinea pig serum and urine contained a sizable quantity of unchanged drug. Dog plasma and urine had significant amounts of nonconjugated 1-(p-hydroxyphenethyl)biguanide and of an unidentified major metabolite. In all three species following intravenous drug administration, unchanged drug contributed significantly to the radioactivity found in blood and urine. The apparent half-lives of phenformin eliminateion were 0.3-0.8 day for guinea pigs and rats and 1-1.5 days for dogs. Urinary excretion data indicate apparent half-lives of approximately 1.3-1.5 days for the elimination of each of the three major metabolites in dogs.
D000818:Animals; D001345:Autoradiography; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D004285:Dogs; D005243:Feces / Q000032:analysis; D006168:Guinea Pigs; D008297:Male; D010629:Phenformin / Q000097:blood / Q000378:metabolism* / Q000652:urine; D051381:Rats; D013045:Species Specificity
D010629:Phenformin