Evidence for a role of cytochrome P450 2D6 and 3A4 in ethylmorphine metabolism.

Article Details

Citation

Liu Z, Mortimer O, Smith CA, Wolf CR, Rane A

Evidence for a role of cytochrome P450 2D6 and 3A4 in ethylmorphine metabolism.

Br J Clin Pharmacol. 1995 Jan;39(1):77-80. doi: 10.1111/j.1365-2125.1995.tb04413.x.

PubMed ID
7756104 [ View in PubMed
]
Abstract

Ethylmorphine is metabolised by N-demethylation (to norethylmorphine) and by O-deethylation (to morphine). The O-deethylation reaction was previously shown in vivo to co-segregate with the O-demethylation of dextromethorphan indicating that ethylmorphine is a substrate of polymorphic cytochrome P450(CYP)2D6. To study further the features of ethylmorphine metabolism we investigated its N-demethylation and O-deethylation in human liver microsomes from eight extensive (EM) and one poor metaboliser (PM) of dextromethorphan. Whereas N-demethylation varied only two-fold there was a 4.3-fold variation in the O-deethylation of ethylmorphine, the lowest rate being observed in the PM. Quinidine, at a concentration of 1 microM, inhibited O-deethylation in microsomes from an EM, but was unable to do so in microsomes from the PM. The immunoidentified CYP2D6 and CYP3A4 correlated with the rates of O-deethylation (r = 0.972) and N-demethylation (r = 0.969), respectively. We conclude that the O-deethylation of ethylmorphine is catalysed by the CYP2D6 in human liver microsomes consistent with previous findings in healthy volunteers.

DrugBank Data that Cites this Article

Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
EthylmorphineCytochrome P450 2D6ProteinHumans
Unknown
Substrate
Details
EthylmorphineCytochrome P450 3A4ProteinHumans
Unknown
Substrate
Details