Extensively metabolised in the liver. Specific data on its metabolism missing. Four references consider it safe.

(To be edited, initial data ST OCT 04) Butyrphenone analgesic used in premedication prior to surgery and as emetic. Used together with fentanyl in neuroleptic anaesthesia. About 75% of the dose is excreted asmetabolites in urine. EPI-list: safe. South African list: use. Australian list: use. French list: authorized.