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Non-Steroidal Anti-Androgen Pregnancy: Not applicable — male-only indication

Bicalutamide

Brand names: Casodex

Adult dose

Dose: 50 mg once daily (combined with GnRH analogue); 150 mg once daily (monotherapy — localised disease)
Route: Oral
Frequency: Once daily
Max: 150 mg/day
50 mg: co-prescribed with GnRH analogue for flare cover (4 weeks) and combined blockade. 150 mg: monotherapy alternative in localised or locally advanced disease where ADT declined

Paediatric dose

Dose: Not applicable N/A/kg
Route: Oral
Frequency: Not applicable
Max: Not applicable
Not applicable

Dose adjustments

Renal

No dose adjustment required

Hepatic

Use with caution; monitor LFTs — hepatotoxicity risk

Paediatric weight-based calculator

Not applicable

Clinical pearls

  • Gynaecomastia occurs in up to 70% on 150 mg monotherapy — prophylactic breast irradiation (single fraction 12 Gy) reduces incidence; tamoxifen 10 mg/day can treat established gynaecomastia
  • MHRA: Monitor LFTs periodically — hepatotoxicity reported; discontinue if transaminases greater than 2x ULN
  • At 50 mg: used to prevent testosterone flare when starting GnRH agonist — start 3 days before GnRH agonist and continue for 4 weeks
  • Unlike castration, bicalutamide monotherapy preserves sexual function and bone density better — relevant for quality-of-life discussions
  • NICE NG131: 150 mg monotherapy not recommended for metastatic disease — survival inferior to castration

Contraindications

  • Women and children (prostate cancer indication is male only)
  • Concomitant terfenadine, astemizole, or cisapride

Side effects

  • Gynaecomastia and breast pain (very common — dose-dependent)
  • Hot flushes
  • Hepatotoxicity (LFT elevation — MHRA monitoring advice)
  • Diarrhoea
  • Nausea
  • Erectile dysfunction
  • Haematuria

Interactions

  • Warfarin (increases INR — monitor closely)
  • Ciclosporin and calcium channel blockers (bicalutamide inhibits CYP3A4)
  • Midazolam (increased levels)

Monitoring

  • LFTs (baseline, regularly during treatment)
  • PSA
  • Testosterone (if combined with GnRH analogue)
  • INR (if on warfarin)

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

Related

Curated clinical cross-links plus same-class fallbacks.

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