abirateron

Abiraterone acetate, sold under the brand name Zytiga, is an oral medication used in the treatment of prostate cancer. It works by selectively inhibiting the enzyme cytochrome P450 17A1 (CYP17A1), which is essential for the production of androgens. By blocking CYP17A1 activity, abiraterone lowers androgen levels not only in the testes but also in the adrenal glands and tumor tissue, slowing the growth of androgen-dependent prostate cancer. Abiraterone is administered with prednisone to mitigate mineralocorticoid-related side effects.

Indications and clinical use

Abiraterone is approved for metastatic castration-resistant prostate cancer (mCRPC) in combination with prednisone for patients whose disease has progressed after androgen-deprivation therapy, including prior chemotherapy with docetaxel. It is also approved in combination with prednisone and ongoing androgen deprivation therapy for metastatic high-risk castration-sensitive prostate cancer, based on trials showing survival benefit in that setting.

Administration and dosing

The typical regimen is abiraterone acetate 1000 mg taken orally once daily with prednisone 5 mg taken twice daily. The drug is intended to be taken on an empty stomach; consuming food around the time of dosing markedly increases absorption and can raise drug levels, so food intake should be avoided near dosing.

Adverse effects and safety

Common adverse effects include hypertension, edema, hypokalemia, liver function test elevations, fatigue, hot flashes, diarrhea, and nausea. Mineralocorticoid excess can lead to fluid retention and electrolyte abnormalities, while liver toxicity requires monitoring. Because abiraterone is a strong CYP3A4 inhibitor, it can interact with other medications and warrants consultation of drug interaction guidelines. Monitoring typically includes regular liver function tests, electrolytes, blood pressure, and assessment of symptoms.

History and development

Abiraterone acetate was developed for targeting androgen synthesis in prostate cancer and received regulatory approval in multiple regions for use in both castration-resistant and certain castration-sensitive disease settings.