Substrate of CYP 3A. Administered in ug dose. References consider it safe for use

(To be edited, initial data ST OCT 04) Opioid analgesic used by way of epidural injection (30-50 ug) in postoperative pain and in caecarian section. Chemically related to fentanyl. Metabolized by CYP 3A4, about 80% of the dose excreted as metabolite within 24 hours. MFM James, RJ Hift. Porphyrias. Br J Anaesth 2000; 85, 143-53: use. South African list: use. French list: use.