COMPARATIVE METABOLISM OF HYDROCODONE IN MAN, RAT, GUINEA-PIG, RABBIT, AND DOG

  • 1 January 1978
    • journal article
    • research article
    • Vol. 6  (4) , 488-493
Abstract
Routes of metabolism of this CNS depressant which is widely used an an antitussive, included O-demethylation, N-dealkylation and 6-keto-reduction to the corresponding 6-.alpha.- and 7-.beta.-hydroxy metabolites. Each metabolic pathway produced an active metabolite. Mean total recovery of drug and metabolites as percentage of administered dose ranged from 10.6% for the rabbit 46.8% for the guinea pig, man was intermediate at 25.7%. For man, approximately 70% of the total drug recovered was excreted in the 1st 24 h, and the remainder by 72 h. Considerable species differences were observed in the patterns of hydrocodone metabolism. Stereoselectivity of 6-keto reductive to the .beta.-form was observed for all species in the reduction of hydrocodone and hydromorphone with the exception of the reduction of hydrocodone in man.