What it's for (Indications)
- Cyproterone acetate is an anti-androgenic agent with progestogenic properties, indicated for several androgen-dependent conditions.
- In males, its primary indications include the reduction of sex drive in cases of sexual deviation where alternative interventions are inappropriate or ineffective, and for anti-androgen therapy in inoperable prostate carcinoma.
- In females, cyproterone acetate is indicated for the treatment of severe forms of androgenization, such as severe hirsutism (excessive hair growth), severe androgenetic alopecia (pattern hair loss), and severe acne and seborrhea that have not responded to other treatments.
- For these female indications, it is often prescribed in lower doses, typically in combination with an estrogen, as part of a cyclical regimen.
- It is also utilized in specific protocols for gender-affirming hormone therapy for transgender women to suppress endogenous testosterone production and effects.
- The selection of cyproterone acetate is typically reserved for severe cases or when first-line therapies are inadequate due to its significant risk profile.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | The dosage of cyproterone acetate varies considerably depending on the specific indication, the patient's sex, and the formulation (e.g., monotherapy tablets vs. combined oral contraceptives). For the reduction of sex drive in males, typical doses range from 50 mg to 100 mg daily, which may be gradually reduced once a satisfactory response is achieved. In the palliative treatment of advanced prostate carcinoma, much higher doses are generally prescribed, ranging from 200 mg to 300 mg daily, administered in divided doses. For severe androgenization in women, doses typically range from 2 mg (as part of a combined oral contraceptive) to 50 mg or 100 mg daily for 10 days of a monthly cycle, always in combination with an estrogen. Treatment duration is individualized, often extending over several months or years. It is crucial that dosing is strictly adhered to as prescribed by a healthcare professional and adjusted based on therapeutic response and adverse event monitoring. |
Safety & Warnings
Common Side Effects
- Cyproterone acetate can cause a range of side effects, some of which are common and others more serious.
- Common side effects in males may include decreased libido, erectile dysfunction, gynecomastia (breast enlargement), fatigue, weight changes, and hot flashes.
- In females, common side effects can include breast tenderness, headache, weight gain or loss, mood changes (including depression), nausea, and irregular menstrual bleeding (though less common when combined with estrogen).
- More serious adverse effects for both sexes include significant hepatotoxicity, which can manifest as jaundice, hepatitis, or even hepatic failure, and is often dose-dependent.
- There is an increased risk of meningioma, particularly with prolonged use and high cumulative doses.
- Thromboembolic events (e.
- g.
- , deep vein thrombosis, pulmonary embolism) are a known risk, especially when cyproterone acetate is combined with an estrogen.
- Adrenal suppression, osteoporosis, and depressive disorders are also noted as potential serious risks.
- Regular monitoring for these adverse events is essential during treatment.
Serious Warnings
- Black Box Warning: **Serious Warnings** Cyproterone acetate is not approved for use by the U.S. Food and Mrug Administration (FDA) and therefore does not carry an FDA-mandated Black Box Warning. However, based on international regulatory guidance and extensive clinical experience, several severe risks warrant explicit and prominent warnings, analogous to a boxed warning. **Hepatotoxicity:** Cyproterone acetate is associated with a significant risk of dose-dependent hepatotoxicity, which can be severe, progressive, and, in rare instances, fatal. Cases of jaundice, hepatitis, and liver failure have been reported. This risk necessitates vigilant monitoring of liver function tests (LFTs) prior to initiating treatment and regularly throughout therapy, especially at higher doses (e.g., for prostate cancer). Treatment must be discontinued immediately if clinically significant liver abnormalities develop or if symptoms such as persistent nausea, vomiting, abdominal pain, dark urine, or jaundice occur. **Meningioma Risk:** There is a well-established and serious risk of meningioma development or growth with cyproterone acetate, particularly with long-term use and high cumulative doses. The risk increases with higher doses and longer duration of treatment. Patients should be thoroughly evaluated for meningioma symptoms (e.g., new or worsening headaches, visual disturbances, hearing loss, seizures, neurological deficits) and undergo appropriate imaging (e.g., MRI) if suspected. If a meningioma is diagnosed, cyproterone acetate treatment must be immediately and permanently discontinued. **Thromboembolic Events:** While less common than hepatotoxicity or meningioma, cyproterone acetate, especially when used in combination with estrogen-containing products (e.g., for severe androgenization in women), significantly increases the risk of serious thromboembolic events, including deep vein thrombosis (DVT), pulmonary embolism (PE), cerebral thrombosis, and myocardial infarction. Patient history of thromboembolic disorders or significant risk factors for thrombosis should be carefully assessed prior to and during treatment. The combination with estrogen further elevates this risk. **Adrenal Suppression:** High doses of cyproterone acetate can lead to adrenal cortical suppression, potentially causing adrenal insufficiency. Patients should be monitored for signs and symptoms of adrenal insufficiency, particularly when discontinuing the drug, and appropriate steroid replacement may be required.
- Patients receiving cyproterone acetate require careful monitoring due to several serious warnings.
- Liver function tests must be performed prior to treatment and regularly during therapy, especially at higher doses, given the risk of dose-dependent hepatotoxicity, which can be severe and fatal.
- Diabetic patients or those with a family history of diabetes should be closely monitored for glucose tolerance, as cyproterone acetate can affect carbohydrate metabolism.
- There is an increased risk of developing meningiomas, particularly with long-term use (several years) and high cumulative doses.
- Patients should be informed about symptoms of meningioma (e.
- g.
- , persistent headache, visual disturbances, neurological deficits), and treatment should be discontinued if a meningioma is diagnosed.
- The risk of thromboembolic events is significant, particularly when used in combination with estrogen-containing products, necessitating careful patient selection and awareness of risk factors.
- High doses can lead to adrenal insufficiency, requiring monitoring of adrenal function.
- Patients should also be monitored for signs of depression, as this medication can exacerbate mood disorders.
- Bone mineral density should be assessed in individuals at risk for osteoporosis, especially with long-term use.
How it Works (Mechanism of Action)
Cyproterone acetate exerts its pharmacological effects through a dual mechanism. Primarily, it functions as a potent anti-androgen. It competitively binds to androgen receptors in target tissues, such as the prostate, hair follicles, and sebaceous glands, thereby preventing endogenous androgens (like testosterone and dihydrotestosterone) from exerting their biological actions. This antagonism leads to a reduction in androgen-dependent symptoms and conditions. Secondly, cyproterone acetate possesses significant progestogenic activity. This progestogenic effect leads to a negative feedback on the hypothalamic-pituitary-gonadal axis, resulting in the suppression of gonadotropin release (luteinizing hormone [LH] and follicle-stimulating hormone [FSH]). The reduction in LH and FSH consequently decreases endogenous androgen production by the testes in males and, to a lesser extent, by the adrenal glands in both sexes. This combined anti-androgenic and central androgen-suppressing action makes it highly effective in conditions driven by excessive or undesirable androgenic activity.
Commercial Brands (Alternatives)
No other brands found for this formula.