Morphine metabolites

Paul D et al Pharmacological characterization of morphine - -glucuronide, a very potent morphine metabolite. J Pharmacol Exp Ther 1989 251 477. [PMID 2810109]... 

Christrup, L.L. Morphine metabolites. Acta Anaesthesiol. Scand. 1997, 41, 116-122. 

Incubation of morphine and [14C-methyl]-5-adenosylmethionine with rabbit liver homogenates resulted in the detection of 2-methoxymorphine as a minor metabolite/446 Oxidation at C-2 may also have occurred in rat brain homogenates with the tentative identification of morphine-2,3-quinone as a minor morphine metabolite/447 Morphine-N-oxide (266) and its 3-glucuronide have been isolated 448 from guinea pig urine after morphine adminstration, and a- and /3-dihydromorphine (264 and 265) were also established as metabolites by gc/ms of extracts of the urine of several species. 

Disposition in the Body. Readily absorbed after oral administration or by injection. Rapidly hydrolysed to 6-monoacetylmorphine in blood and then more slowly metabolised to morphine which is the major active metabolite normorphine is also formed to a minor extent small quantities of codeine are occasionally seen in the urine of addicts, but this is thought to arise from the presence of acetylcodeine as an impurity in illicit heroin samples. All metabolites may be conjugated with glucuronic acid. Up to 80% of a dose is excreted in the urine in 24 hours, mainly as morphine-3-glucuronide with about 5 to 7% of the dose as free morphine, 1% as 6-monoacetylmorphine, 0.1 % as unchanged drug, and trace amounts of other metabolites after inhalation, 14 to 20% of the dose appears in the urine morphine metabolites are excreted in the bile. 

Morphine metabolites Opium alkaloids Synthetic TTiebaine... 

Isolation and Identification of Morphine 3- and 6-Glucuronides, Morphine 3,6-Diglucuronide, Morphine 3-Etherel Sulfate, Normorphine and Normorphine 6-Glucuronide as Morphine Metabolites in Humans J. Pharm. Sci. 66(9) 1288-1293 (1977) CA 88 4463z... 

Oprelvekin An interaction of oprelvekin (50 micrograms/kg/day) with morphine (120 mg orally bd) was suggested as the probable cause of respiratory depression and sedation in a 20-year-old woman with thrombocytopenia associated with chemotherapy [116 ]. Oprelvekin was thought to have reduced the renal excretion of morphine metabolites. 

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