Drug Information for OXYCONTIN (OXYCODONE HCl CONTROLLED-RELEASE) TABLETS CII10 mg 15 mg 20 mg 30 mg 40 mg 60 mg* 80 mg* 160 mg* (Purdue Pharma LP): Metabolism

Oxycodone hydrochloride is extensively metabolized to noroxycodone, oxymorphone, noroxymorphone, and their glucuronides. The major circulating metabolite is noroxycodone. Noroxycodone is reported to be a considerably weaker analgesic than oxycodone. Oxymorphone, although possessing analgesic activity, is present in the plasma only in low concentrations. The correlation between oxymorphone concentrations and opioid effects was much less than that seen with oxycodone plasma concentrations. The analgesic activity profile of other metabolites is not known.

CYP3A mediated N-demethylation (to noroxycodone) is the primary metabolic pathway of oxycodone with a lower contribution from CYP2D6 mediated O-demethylation (to oxymorphone). Therefore, the formation of these and related metabolites can, in theory, be affected by other drugs (see Drug-Drug Interactions).