Generic Name and Formulations:
Enzalutamide 40mg; soft gelatin caps.
Astellas Pharma US, Inc.
|Approved for metastatic castration-resistant prostate cancer.|
Treatment of metastatic castration-resistant prostate cancer.
Swallow whole. 160mg once daily. Dose modifications: ≥Grade 3 toxicity or intolerable side effect: withhold dosing for 1 week or until symptoms improve to ≤Grade 2, then resume at same or reduced dose (120mg or 80mg), if warranted. Concomitant strong CYP2C8 inhibitors: avoid if possible. If co-administration necessary, reduce enzalutamide dose to 80mg once daily; if inhibitor is discontinued, return enzalutamide dose to the dose used prior to initiation of inhibitor.
Androgen receptor inhibitor.
Risk of seizure; permanently discontinue if develops during treatment. Severe renal or hepatic impairment. Nursing mothers: not recommended.
Avoid concomitant strong CYP2C8 inhibitors (eg, gemfibrozil) if possible; reduce enzalutamide dose if cannot be avoided. Avoid concomitant CYP2C8 inducers (eg, rifampin), CYP3A4 inducers (eg, carbamazepine, phenobarbital, phenytoin, rifabutin, rifampin, rifapentine, bosentan, efavirenz, etravirine, modafinil, nafcillin), and St. John’s Wort if possible. Potentiated by CYP3A4 inhibitors (itraconazole). Antagonizes midazolam (CYP3A4 substrate), warfarin (CYP2C9 substrate), and omeprazole (CYP2C19 substrate). Avoid concomitant drugs with narrow therapeutic indexes metabolized by CYP3A4 (eg, alfentanil, cyclosporine, dihydroergotamine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, tacrolimus), CYP2C9 (eg, phenytoin, warfarin), CYP2C19 (eg, S-mephenytoin); enzalutamide may decrease their exposure. Caution with concomitant drugs that may lower the seizure threshold. Conduct more INR monitoring if concomitant warfarin cannot be avoided.
Asthenia/fatigue, back pain, decreased appetite, constipation, arthralgia, diarrhea, hot flush, upper respiratory tract infection, peripheral edema, dyspnea, musculoskeletal pain, weight decreased, headache, hypertension, dizziness/vertigo.
Hepatic (CYP2C8, 3A4); 98% protein bound.