abiraterone acetate + rifampicin

**Abiraterone acetate + rifampicin** is a non-standard, co-administered oral drug combination consisting of abiraterone acetate, a prodrug of abiraterone, and rifampicin, an antibiotic and potent CYP3A4 inducer. Abiraterone acetate is used primarily for metastatic castration-resistant or castration-sensitive prostate cancer. It works by inhibiting CYP17A1 (17α-hydroxylase/C17,20-lyase), reducing androgen production critical for prostate cancer progression. Rifampicin is a first-line treatment for tuberculosis and other bacterial infections but is notable here for its strong induction of hepatic CYP3A4, which substantially accelerates the metabolism of abiraterone, leading to ~50% reduced systemic exposure and AUC of abiraterone. This combination is generally not recommended due to the risk of reduced abiraterone effectiveness, and strong inducers like rifampicin are advised to be avoided or used only with clinical monitoring if co-administration is necessary[1][3][4][5].