title: Urinary excretion of meperidine and its metabolites.
abstract: The urine of male and female mice, rats, guinea pigs, rabbits, cats, and dogs, given meperidine hydrochloride, 20--40 mg/kg ip, was analyzed by GLC for meperidine, normeperidine, p-hydroxymeperidine, and total (free and conjugated) meperidinic and normeperidinic acids. More than 90% of the excreted drugs was found in the 24-hr urine. Meperidine was observed in the urine of mice, rats, guinea pigs, and cats, but only a trace amount was observed in the urine of rabbits and dogs. Normeperidine, p-hydroxymeperidine (except in the mice), and total meperidinic and normeperidinic acids were observed in all species. All of the species studied have the capacity to N-demethylate meperidine to normeperidine and to hydrolyze meperidine and normeperidine to their respective acids. The male has a higher N-demethylating activity that the female with the exception of mice. Ester hydrolysis is a major metabolic pathway for meperidine metabolism.
mesh_terms: D000818:Animals; D002415:Cats; D004285:Dogs; D005260:Female; D006168:Guinea Pigs; D006863:Hydrogen-Ion Concentration; D008297:Male; D008614:Meperidine / Q000031:analogs & derivatives / Q000494:pharmacology / Q000652:urine*; D051379:Mice; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity
chemical_list: D008614:Meperidine; C002752:normeperidine