Inhibitory effects of anticancer drugs on dextromethorphan-O-demethylase activity in human liver microsomes.

Article Details

Citation

Le Guellec C, Lacarelle B, Catalin J, Durand A

Inhibitory effects of anticancer drugs on dextromethorphan-O-demethylase activity in human liver microsomes.

Cancer Chemother Pharmacol. 1993;32(6):491-5.

PubMed ID
8258200 [ View in PubMed
]
Abstract

The dextromethorphan-O-demethylase activity determined in human liver microsomes was used to screen various anticancer drugs for their ability to inhibit this cytochrome CYP2D6-dependent activity. Competitive inhibition indicates that the drug binds the enzyme and is potentially subjected to a polymorphic metabolism. Among the 13 anticancer drugs tested, 4 compounds caused competitive inhibition of dextromethorphan-O-demethylation: lomustine (Ki = 7.7 microM), doxorubicin (Ki = 75 microM), vinorelbine (Ki = 22 microM), and vinblastine (Ki = 42 microM). The results of these studies indicate that the metabolism of the drugs concerned is possibly altered in poor metabolizers of debrisoquine and requires further investigation to study their specific routes of biotransformation. The metabolism of these drugs probably involves various biotransformation pathways, among which the CYP2D6-dependent route would be of minor importance. A second hypothesis is that these drugs could be inhibitors of the isozyme without being a substrate.

DrugBank Data that Cites this Article

Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
DoxorubicinCytochrome P450 2D6ProteinHumans
No
Substrate
Inhibitor
Details
LomustineCytochrome P450 2D6ProteinHumans
Unknown
Inhibitor
Details
VinblastineCytochrome P450 2D6ProteinHumans
Unknown
Inhibitor
Details
VinorelbineCytochrome P450 2D6ProteinHumans
No
Inhibitor
Details