Flutamide

How it works

It competitively blocks androgen receptors in target tissues, preventing dihydrotestosterone and testosterone from stimulating prostate tumour growth.

Prescribing in practice

• Hepatotoxicity, including fatal hepatic failure, is the key risk; check liver function before and periodically during treatment and stop promptly if jaundice or transaminase rise occurs.
• When used for prostate cancer it is typically combined with castration (medical or surgical) to achieve complete androgen blockade.
• Counsel that it is not indicated in women or children and review interacting drugs, including warfarin, against current prescribing references.

Monitoring

Monitor liver function tests at baseline and at regular intervals, with prompt re-checking if symptoms of hepatic dysfunction arise.

Counselling the patient

• Report yellowing of the skin or eyes, dark urine, nausea or right-sided abdominal pain straight away.
• Gynaecomastia and breast tenderness are common; tell your team if troublesome.
• Urine may take on an amber or greenish discolouration, which is harmless.

Evidence & guidelines

Anti-androgens combined with castration are established in prostate cancer management as reflected in UK and international oncology guidance.