[13] Abiraterone acetate is used in combination with prednisone, a corticosteroid, as a treatment for mCRPC (previously called hormone-resistant or hormone-refractory prostate cancer).

Abiraterone acetate has received Food and Drug Administration (FDA) (28 April 2011), European Medicines Agency (EMA) (23 September 2011), Medicines and Healthcare products Regulatory Agency (MHRA) (5 September 2011) and Therapeutic Goods Administration (TGA) (1 March 2012) approval for this indication.

[2][6][5][4] In Australia it is covered by the Pharmaceutical Benefits Scheme when being used to treat castration-resistant prostate cancer and given in combination with prednisone/prednisolone (subject to the conditions that the patient is not currently receiving chemotherapy, is either resistant or intolerant of docetaxel, has a WHO performance status of <2, and his disease has not since become progressive since treatment with PBS-subsidised abiraterone acetate has commenced).

[2] There is no specific antidote for abiraterone acetate overdose, and treatment should consist of general supportive measures, including monitoring of cardiac and liver function.

[2] Abiraterone acetate is a CYP3A4 substrate and hence should not be administered concurrently with strong CYP3A4 inhibitors such as ketoconazole, itraconazole, clarithromycin, atazanavir, nefazodone, saquinavir, telithromycin, ritonavir, indinavir, nelfinavir, voriconazole) or inducers such as phenytoin, carbamazepine, rifampin, rifabutin, rifapentine, phenobarbital.

[19][18] Spironolactone generally exerts anti-androgenic effects, but experimental evidence exists that it acts as an androgen receptor agonist in an androgen-depleted environment, capable of inducing prostate cancer proliferation.

Inhibition of CYP17A1 activity by abiraterone acetate thus decreases circulating levels of androgens such as DHEA, testosterone, and dihydrotestosterone (DHT).

[25] In accordance with its antiandrogenic action, abiraterone acetate decreases the weights of the prostate gland, seminal vesicles, and testes.

[31] There has been interest in the use of abiraterone acetate for the treatment of breast cancer due to its ability to lower estrogen levels.

[32] However, abiraterone has been found to act as a direct agonist of the estrogen receptor, and induces proliferation of human breast cancer cells in vitro.

[32] In spite of its antiandrogenic and estrogenic properties, abiraterone acetate does not appear to produce gynecomastia as a side effect.

[34] This is why the medication is combined with prednisone, a corticosteroid, which serves as a means of glucocorticoid replacement and prevents mineralocorticoid excess.

[35] Abiraterone acetate, along with galeterone, has been identified as an inhibitor of sulfotransferases (SULT2A1, SULT2B1b, SULT1E1), which are involved in the sulfation of DHEA and other endogenous steroids and compounds, with Ki values in the sub-micromolar range.

With the nonsteroidal androgen synthesis inhibitor ketoconazole as a model, they developed abiraterone acetate, filing a patent in 1993 and publishing the first paper describing it the following year.

[40] Abiraterone acetate was approved by the United States Food and Drug Administration on 28 April 2011 for mCRPC.

[44] Until May 2012 the National Institute for Health and Clinical Excellence (NICE) did not recommend use of the drug within the NHS on cost-effectiveness grounds.

[61] Abiraterone acetate may be useful for prevention of the testosterone flare at the initiation of GnRH agonist therapy in men with prostate cancer.