Cyproteron

Additional information

Cyproterone is an antiandrogen with different indications in men and women. In men, it is primarily used to decrease the sex-drive in men with paraphilia or in sex offenders [1-2]. but also in prostate cancer [3]. In fertile women, it is used to treat extensive hirsutism [1-2]. The substance is also one of the main antiandrogen medications used in feminizing hormone therapy in transgender men [4].

In combination with ethinylestradiol cyproterone is used for treatment of moderate to severe acne or hirsutism in women [1-2]. It might also be used as an oral contraceptive drug in women but this is not a primary indication.

Pharmacokinetics and dosing

No studies comparing pharmacokinetic properties in men and women have been found. One small study in healthy men (n=28, ages 22-74 years) found an age-dependent change in apparent clearance and volume of distribution causing a longer terminal half-life of cyproterone in older men [5].

Effects

Cyproterone is used on different indications in men and women and thus comparison of effects is not relevant.

Adverse effects

The most common reported adverse events in men are decreased libido, erectile dysfunction, and reversible inhibition of the spermatogenesis. In women, the most commonly reported adverse events are spot bleedings, increased weight, and depression [1]. The most severe adverse events in both men and women are hepatotoxicity, benign and malignant hepatic tumors which may lead to intraabdominal bleeding, and thromboembolic events [1]. In rats, considerably higher doses (five-fold) have been needed to induce hepatic tumors [6].

Meningioma is an uncommon adverse effect of cyproterone treatment [7]. An observational retrospective cohort study from Spain (130 men, 326 women with meningiomas identified in 2 137 191 persons of which 2 474 used high dose cyproterone) found an increased risk of meningioma in those with high doses of cyproterone during a period of at least 2 years of 11.4 (95% CI 4.3, 30.8) (8). Women were found to have a risk ratio of 2.0 compared to men [7].

Reproductive health issues

Regarding teratogenic aspects, please consult the Drugs and Birth Defects Database (in Swedish, Janusmed fosterpåverkan).