Cyproterone Acetate Therapy

Indications and Usage

Cyproterone acetate is used as a second-line hormonal therapy for androgen-sensitive metastatic prostate cancer in Europe and Canada, as recommended by the European medical community 1, 2
The American medical community suggests that cyproterone acetate can reduce tumor flare when initiating LHRH agonist therapy for prostate cancer 2
The medical community notes that cyproterone acetate is less effective than goserelin when used alone for delaying progression of metastatic prostate cancer 2
The World Professional Association for Transgender Health recommends cyproterone acetate as an antiandrogen component in hormone therapy for transgender women/transfeminine individuals 2, 3

The medical community recommends complete blood count to establish baseline hemoglobin and hematocrit, with ongoing monitoring every 3-6 months 3
The American medical community suggests liver function tests at baseline and every 3-6 months, due to risk of hepatotoxicity, including potential for fulminant hepatic failure 2, 3
Adrenal function assessment is recommended at baseline and periodically throughout treatment, as suggested by the medical community 3
The medical community notes that regular monitoring for anemia, adrenal suppression, and hepatotoxicity is necessary during cyproterone acetate therapy 2, 3

The medical community recommends discontinuation of cyproterone acetate in case of development of fulminant hepatic failure or severe hepatotoxicity, severe anemia, or significant adrenal suppression 2, 3
The American medical community suggests consideration of discontinuation in case of persistent moderate elevation of liver enzymes 2

The medical community notes that cyproterone acetate is contraindicated in patients with hereditary angioedema, and should be used with caution in patients with pre-existing liver disease 2
The World Professional Association for Transgender Health recommends careful consideration of discontinuation in transgender women/transfeminine individuals, as it may result in significant exacerbation of gender dysphoria, potential depression and/or anxiety 3
The medical community suggests that cyproterone acetate shows fewer cardiovascular side effects compared to diethylstilbestrol in prostate cancer treatment 2

The World Professional Association for Transgender Health recommends cyproterone acetate as an antiandrogen component in hormone therapy for transgender women, and it is used for recurrent ischemic priapism prevention and vasomotor symptoms in cancer patients in countries where it is available 4, 5

For prostate cancer, the American Society of Clinical Oncology suggests using first-generation antiandrogens such as flutamide, nilutamide, or bicalutamide in combined androgen blockade regimens, or second-generation antiandrogens like enzalutamide, apalutamide, or darolutamide for more potent androgen receptor blockade 6
For transgender care, bicalutamide may be used off-label as an alternative antiandrogen, though with a different side effect profile 6