Abiraterone acetate is an oral prodrug converted to abiraterone after administration. Abiraterone inhibits CYP17, an enzyme system with 17α-hydroxylase and C17,20-lyase activities that are important for steroid and androgen production.
Simple explanation
Prostate cancer can depend on androgen signaling. Testosterone and related hormones activate the androgen receptor pathway, which can support prostate cancer-cell survival and growth.
Abiraterone reduces androgen production by blocking CYP17-mediated steroid synthesis. This lowers androgen availability beyond the effect achieved by conventional suppression of testicular testosterone production alone.
Detailed mechanism
CYP17 participates in steroidogenesis in the testes, adrenal glands and other tissues. By inhibiting CYP17, abiraterone reduces the production of testosterone and other androgen precursors.
This pharmacologic effect is central to its role as an androgen-deprivation strategy in advanced prostate cancer.
Why prednisone is used
CYP17 inhibition can alter steroid hormone production and increase mineralocorticoid-related effects. Corticosteroid administration helps manage this hormonal imbalance and is incorporated into the labeled treatment regimen.
Mechanism and adverse effects
The same biological mechanism that reduces androgen synthesis contributes to mineralocorticoid-related adverse effects, including hypertension, hypokalemia and fluid retention.