Identification of carboxylesterase-dependent dabigatran etexilate hydrolysis.

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Citation

Laizure SC, Parker RB, Herring VL, Hu ZY

Identification of carboxylesterase-dependent dabigatran etexilate hydrolysis.

Drug Metab Dispos. 2014 Feb;42(2):201-6. doi: 10.1124/dmd.113.054353. Epub 2013 Nov 8.

PubMed ID
24212379 [ View in PubMed
]
Abstract

Dabigatran etexilate (DABE) is an oral prodrug that is rapidly converted to the active thrombin inhibitor, dabigatran (DAB), by serine esterases. The aims of the present study were to investigate the in vitro kinetics and pathway of DABE hydrolysis by human carboxylesterase enzymes, and the effect of alcohol on these transformations. The kinetics of DABE hydrolysis in two human recombinant carboxylesterase enzymes (CES1 and CES2) and in human intestinal microsomes and human liver S9 fractions were determined. The effects of alcohol (a known CES1 inhibitor) on the formation of DABE metabolites in carboxylesterase enzymes and human liver S9 fractions were also examined. The inhibitory effect of bis(4-nitrophenyl) phosphate on the carboxylesterase-mediated metabolism of DABE and the effect of alcohol on the hydrolysis of a classic carboxylesterase substrate (cocaine) were studied to validate the in vitro model. The ethyl ester of DABE was hydrolyzed exclusively by CES1 to M1 (Km 24.9 +/- 2.9 muM, Vmax 676 +/- 26 pmol/min per milligram protein) and the carbamate ester of DABE was exclusively hydrolyzed by CES2 to M2 (Km 5.5 +/- 0.8 muM; Vmax 71.1 +/- 2.4 pmol/min per milligram protein). Sequential hydrolysis of DABE in human intestinal microsomes followed by hydrolysis in human liver S9 fractions resulted in complete conversion to DAB. These results suggest that after oral administration of DABE to humans, DABE is hydrolyzed by intestinal CES2 to the intermediate M2 metabolite followed by hydrolysis of M2 to DAB in the liver by CES1. Carboxylesterase-mediated hydrolysis of DABE was not inhibited by alcohol.

DrugBank Data that Cites this Article

Drugs
Drug Enzymes
DrugEnzymeKindOrganismPharmacological ActionActions
Dabigatran etexilateCocaine esteraseProteinHumans
Unknown
Substrate
Details
Dabigatran etexilateLiver carboxylesterase 1ProteinHumans
Unknown
Substrate
Details
Drug Reactions
Reaction
Details
Details