PHARMACOKINETICS OF INTRAVENOUSLY ADMINISTERED NICOMORPHINE AND ITS METABOLITES AND GLUCURONIDE CONJUGATES IN SURGICAL PATIENTS

After intravenous administration of 3,6-dinicotinoylmorphine (nicomorp hine) 30, 20 and 1Omg to patients undergoing surgery, this agent is ra pidly metabolised into the metabolites 6-mononicotinoylmorphine (6MNM) and morphine. The elimination half-lives are 1 minute for nicomorphin e, 13 minutes for 6MNM and 120 minutes for morphine. Morphine is subse quently metabolised into morphine-3-glucuronide (M3G) and morphine-6-g lucuronide (M6G). The half-life of these 2 glucuronide conjugates is s imilar, about 225 minutes. A glucuronide conjugate of 6MNM was not det ected. The area under the serum concentration-time curve of nicomorphi ne and its metabolites is linearly related to the dose.