title: Simultaneous determination of multiple CYP inhibition constants using a cocktail-probe approach.
abstract: To identify cytochrome P450 (CYP) drug-drug interaction (DDI) potential of a new chemical entity, the use of a specific clinically relevant probe substrate in the presence of a test compound is common place. In early discovery of new chemical entities, a balance of rigor, the ability to predict clinical DDI, and throughput is desired in an in vitro assay. This chapter describes a high-throughput CYP-mediated DDI assay method that balances these characteristics. The method utilizes a cassette approach using a cocktail of five selective probe substrates for the major clinically relevant CYPs involved in drug interactions. CYP1A2, 2C9, 2C19, 2D6, and 3A activities are assessed with liquid chromatography/tandem mass spectrometry (LC-MS/MS) quantification of metabolite formation. The method also outlines specific inhibitors to evaluate dynamic range and as a positive control. The benefits and needs for caution of this method are noted and discussed.
authors.affiliation: Pfizer Inc., La Jolla, CA, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Zientek
authors.forename: Kuresh
authors.initials: K
authors.lastname: Youdim
mesh_terms: D065607:Cytochrome P-450 Enzyme Inhibitors; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D020128:Inhibitory Concentration 50; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism; D015336:Molecular Probe Techniques
chemical_list: D065607:Cytochrome P-450 Enzyme Inhibitors; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D003577:Cytochrome P-450 Enzyme System