Background: Enzalutamide, registered for the treatment of metastatic castration-resistant prostate cancer (mCRPC), is an inducer of multiple CYP-enzymes. Enzalutamide itself is mainly converted by CYP2C8 to the active metabolite N-desmethylenzalutamide (NDME). Due to a pharmacokinetic interaction, combining enzalutamide with a moderate CYP2C8 inhibitor might result in higher enzalutamide concentrations. Addressing this interaction is challenging since pharmacokinetic data are missing.
Case presentation: We present a case of a Caucasian male with mCRPC who was treated with enzalutamide and a moderate CYP2C8 inhibitor, clopidogrel, concomitantly. Plasma trough levels (Ctrough) of enzalutamide and its active metabolite N-desmethylenzalutamide (NDME) were determined and compared when treated with and without clopidogrel. The sum concentration of enzalutamide and NDME was not affected by coadministration of a moderate CYP2C8 inhibitor. Both treatments were well tolerated and no major side effect were observed.
Conclusion: This case report shows that enzalutamide can be safely prescribed while cotreated with a moderate CYP2C8-inhibitor, without reducing the dose. More research is warranted to make a statement about the effect of enzalutamide on clopidogrel.
Keywords: Castration-resistant prostate cancer; Clopidogrel; Drug–drug interaction; Enzalutamide; Exposure; Moderate CYP2C8 inhibitors; Pharmacokinetics.
© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.