Steroidal Anti-Androgen Pregnancy: Not applicable — male indication; women: contraception required during use

Cyproterone Acetate

Brand names: Cyprostat

Adult dose

Dose: 100-300 mg/day in divided doses (prostate cancer)

Route: Oral

Frequency: Two to three times daily with meals

Max: 300 mg/day

For hot flush suppression during GnRH analogue therapy: 50-100 mg twice daily. For flare cover: 200-300 mg/day started 3 days before GnRH agonist

Paediatric dose

Dose: Seek specialist opinion N/A/kg

Route: Oral

Frequency: Seek specialist opinion

Max: Seek specialist opinion

Seek specialist opinion

Dose adjustments

Renal

Use with caution

Hepatic

Contraindicated in hepatic impairment — hepatotoxic; regular LFT monitoring mandatory

Paediatric weight-based calculator

Patient weight (kg)

Seek specialist opinion

Clinical pearls

MHRA 2020 safety alert: Cyproterone acetate associated with increased risk of meningioma (benign brain tumour), particularly at cumulative doses above 25 g — monitor for neurological symptoms; conduct MRI if symptoms arise
Significant hepatotoxicity risk — LFTs mandatory before starting and regularly throughout treatment; use contraindicated with existing hepatic impairment
Thromboembolism risk: warn patients about DVT/PE symptoms; use with caution in patients with cardiovascular risk
Largely superseded by newer anti-androgens (bicalutamide, enzalutamide, darolutamide) in prostate cancer; still used for hot flush management on ADT
Meningioma risk is cumulative dose-dependent — reassess benefit-risk if long-term high-dose use planned

Contraindications

Hepatic impairment
History of meningioma or thromboembolic disease
Sickle cell anaemia
Severe depression or suicidal ideation

Side effects

Hepatotoxicity (dose-dependent — can be fatal)
Thromboembolism
Fatigue
Gynaecomastia
Loss of libido and erectile dysfunction
Meningioma (long-term use — MHRA 2020)
Depression

Interactions

Alcohol (increased hepatotoxicity)
Warfarin (altered anticoagulant requirements)
Other hepatotoxic drugs (additive risk)

Monitoring

LFTs (before starting, then every 2-3 months)
MRI brain if neurological symptoms (meningioma surveillance)
Thromboembolic events
PSA

Reference: BNFc; BNF 90; MHRA Drug Safety Update 2020 (cyproterone and meningioma); NICE NG131; EAU Guidelines 2024. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways