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Anti-androgen (steroidal)

Cyproterone acetate

Brand names: Cyprostat, Androcur

Cyproterone acetate is a steroidal anti-androgen with progestogenic activity, used in prostate cancer, to suppress the testosterone 'flare' with GnRH analogues, and for severe hypersexuality. The overview context here is its anti-androgen use in urology.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It blocks androgen receptors and also suppresses gonadotrophin release, thereby lowering testosterone and reducing androgenic stimulation of prostatic tissue.

Prescribing in practice

  • Dose- and duration-dependent hepatotoxicity, including fatal hepatic failure, can occur, so liver function must be monitored and treatment stopped if significant abnormality develops.
  • A risk of meningioma has been identified, particularly with prolonged higher-dose use, prompting MHRA advice to use the lowest effective exposure and review the need for treatment.
  • It can impair adrenocortical function and cause thromboembolism, so caution is needed in cardiovascular and diabetic patients per the SPC.

Monitoring

Monitor liver function and blood counts periodically, assess adrenal function where relevant, and remain alert to neurological symptoms suggesting meningioma.

Counselling the patient

  • Report jaundice, dark urine, or persistent abdominal discomfort without delay.
  • Tell your doctor about new or worsening headaches, visual changes, or seizures.
  • Tiredness and reduced libido are expected effects of treatment.

Evidence & guidelines

Long-used anti-androgen in prostate cancer and hypersexuality, with regulatory safety reviews refining its dosing because of hepatic and meningioma risks.

Reference: NICE NG131; MHRA Drug Safety Update; BAD; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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