![Sample our Bioscience journals, sign in here to start your access, Latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5925/TOC-Subject-Sample-2021-Bioscience.jpg"})
Abstract
1. Metabolites of codeine were determined by use of h.p.l.c. in urine of male mice, rats, guinea pigs and rabbits injected with 10mg codeine/kg subcutaneously.
2. In 24 h urines of these species, unchanged codeine, codeine glucuronide, free morphine, and morphine-3-glucuronide were as follows: mice, 6.8,1.6, 0.8 and 7.6% dose; rats, 1.6, 0.2, 4.3 and 23.9% dose; guinea pigs, 1.6, 39.8, 0.2 and 1.6% dose; rabbits, 2.2, 24.5, 1.3 and 17.9% dose. Urinary excretion of morphine-6-glucuronide was 0.7% dose in guinea pigs, 1.9% in rabbits, and not detectable in mice and rats. Norcodeine was found only in the urine of mice.
3. These results indicate that codeine is metabolized in all four species by glucuronid-ation and by oxidative N- and O-demethylation, but the quantitative excretions of metabolites were quite different in different species.