Stereoselective interactions of warfarin enantiomers with the pregnane X nuclear receptor in gene regulation of major drug-metabolizing cytochrome P450 enzymes.

Article Details

Citation

Rulcova A, Prokopova I, Krausova L, Bitman M, Vrzal R, Dvorak Z, Blahos J, Pavek P

Stereoselective interactions of warfarin enantiomers with the pregnane X nuclear receptor in gene regulation of major drug-metabolizing cytochrome P450 enzymes.

J Thromb Haemost. 2010 Dec;8(12):2708-17. doi: 10.1111/j.1538-7836.2010.04036.x.

PubMed ID
20735727 [ View in PubMed
]
Abstract

BACKGROUND: Warfarin, an antagonist of vitamin K, is an oral coumarin anticoagulant widely used to control and prevent thromboembolic disorders. Warfarin is clinically available as a racemic mixture of R- and S-warfarin. The S-enantiomer has three to five times greater anticoagulation potency than its optical congener. Recently, vitamin K(2) function has been proposed via the pregnane X receptor (PXR) in osteocytes. PXR acts as a xenobiotic sensor that controls expression of many genes involved in drug/xenobiotic metabolic clearance. OBJECTIVE: The aim was to examine whether enantiomers of warfarin stereoselectively interact with PXR to up-regulate main drug/xenobiotic-metabolizing enzymes of the cytochrome P450 superfamily. METHODS: Interactions of warfarin enantiomers with PXR were tested by gene reporter assays and time-resolved fluorescence resonance energy transfer technology (TR-FRET) ligand binding assay. Up-regulation of PXR-target gene mRNAs by warfarin enantiomers was studied using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) in primary human hepatocytes. RESULTS: We found that R-warfarin interacts with the PXR nuclear receptor. Consistently, R-warfarin significantly induced CYP3A4 and CYP2C9 mRNAs in cultures of primary human hepatocytes or in LS174T intestinal cells. On the other hand, S-warfarin is a less potent inducer of PXR-target genes in human hepatocytes and activates PXR only at supraphysiological concentrations. In addition, we showed that racemic 10- and 4'-hydroxywarfarins are also highly potent PXR ligands and inducers of CYP3A4 and CYP2C9 mRNA in human hepatocytes. CONCLUSION: We showed that R-warfarin can significantly up-regulate major drug-metabolizing enzymes CYP3A4 and CYP2C9 in the liver and thus may cause drug-drug interactions (DDI) with co-administered drugs. The results warrant reconsideration of racemic warfarin usage in clinics.

DrugBank Data that Cites this Article

Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
WarfarinNuclear receptor subfamily 1 group I member 2ProteinHumans
Unknown
Not AvailableDetails
Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
WarfarinCytochrome P450 2C9ProteinHumans
Unknown
Substrate
Inducer
Details
WarfarinCytochrome P450 3A4ProteinHumans
Unknown
Substrate
Inducer
Details
Drug Interactions
DrugsInteraction
Acenocoumarol
Amitriptyline
The therapeutic efficacy of Acenocoumarol can be decreased when used in combination with Amitriptyline.
Warfarin
Amitriptyline
The therapeutic efficacy of Warfarin can be decreased when used in combination with Amitriptyline.
Pharmaco-transcriptomics
DrugDrug GroupsGeneGene IDChangeInteractionChromosome
WarfarinApprovedCYP2C91559
upregulated
[Warfarin binds to and results in increased activity of NR1I2 protein] which results in increased expression of CYP2C9 mRNA10q23.33
WarfarinApprovedCYP3A41576
upregulated
[Warfarin binds to and results in increased activity of NR1I2 protein] which results in increased expression of CYP3A4 mRNA7q22.1