[Pilot study of dose dependence in glucuronidation of morphine to morphine-3- and morphine-5-glucuronide]

In the capacity of an initial study both, the half-lives of morphine and its metabolites morphine-3-glucuronide and morphine-6-glucuronide as well as the ratio of concentrations in the development of time using two different dosages were determined and shown by comparison. A bolus of 10 mg (10 micrograms) tritium-marked morphine was administered intravenously. Subsequently the half-lives of morphine, morphine-3-glucuronide and morphine-6-glucuronide in serum, saliva and urine were determined. To achieve this, morphine and its glucuronides were separated via HPLC and then quantified by measuring the radioactivity. In addition to the short half-lives of morphine and morphine-glucuronides long half-lives were found in the range of 12.6 to 20 hours in serum and urine. There was no positive evidence for glucuronides in saliva. In urine the morphine/glucuronide ratio showed a linear resp. exponential development dependent of dose.