GnRH Agonist — Androgen Deprivation Therapy Pregnancy: Contraindicated in pregnancy

Goserelin

Brand names: Zoladex

Adult dose

Dose: 3.6 mg SC every 28 days; 10.8 mg SC every 12 weeks

Route: Subcutaneous implant (anterior abdominal wall)

Frequency: Monthly (3.6 mg) or 3-monthly (10.8 mg)

Max: As per formulation

Pre-loaded syringe implant. Same testosterone flare precautions as leuprorelin — co-prescribe anti-androgen cover for first 4 weeks

Paediatric dose

Dose: Seek specialist opinion N/A/kg

Route: SC

Frequency: Seek specialist opinion

Max: Seek specialist opinion

Seek specialist opinion

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required

Paediatric weight-based calculator

Patient weight (kg)

Seek specialist opinion

Clinical pearls

Pharmacologically equivalent to leuprorelin; choice between agents often based on patient preference (injection site, frequency) and local formulary
Also used in women for endometriosis, uterine fibroids, and breast cancer (premenopausal hormone-sensitive disease)
In combined androgen blockade (CAB): goserelin + bicalutamide — modest survival benefit over ADT monotherapy but significantly more side effects
Testosterone flare can cause acute urinary obstruction in patients with large prostate or pelvic disease — ensure anti-androgen cover
NICE NG131: ADT should be offered to men with metastatic prostate cancer; may be combined with docetaxel or abiraterone in fit patients with high-volume disease

Contraindications

Hypersensitivity to GnRH analogues
Undiagnosed vaginal bleeding (women)

Side effects

Hot flushes
Sexual dysfunction
Bone density loss
Fatigue
Metabolic effects
Gynaecomastia
Testosterone flare on initiation

Interactions

QT-prolonging drugs (additive risk)
Antidiabetics (monitor glucose — testosterone suppression alters insulin sensitivity)

Monitoring

Testosterone level (castrate level under 50 ng/dL)
PSA
Bone mineral density
Metabolic parameters

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

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Leuprorelin Acetate · GnRH Agonist — Androgen Deprivation Therapy

Pathways