Goserelin — Drug Monograph

Brand names: Zoladex

Drug class: Hormonal Agent

Mechanism of Action

Goserelin is a synthetic decapeptide analogue of naturally occurring gonadotropin-releasing hormone (GnRH). It acts as a potent agonist of pituitary GnRH receptors. Like all GnRH agonists, goserelin first causes a transient surge in LH, FSH, and testosterone/estradiol during the first 1–2 weeks of therapy (the initial "flare") before chronic administration leads to receptor downregulation and pituitary desensitization, which results in a marked decrease in the production of LH and FSH. In men, this causes serum testosterone to fall to castrate levels within 2–4 weeks; in women, serum…

FDA Indications

• Palliative treatment of advanced carcinoma of the prostate
• Adjuvant treatment in combination with flutamide and radiation therapy for Stage B2-C prostatic carcinoma
• Management of endometriosis
• Use as an endometrial thinning agent prior to endometrial ablation
• Palliative treatment of advanced breast cancer in pre- and perimenopausal women

Common Side Effects

• Hot flashes
• Sexual dysfunction
• Injection site reactions (pain, bruising)
• Sweating
• Gynecomastia
• Headache
• Vaginal dryness (women)
• Lethargy

Clinical Pearl

The goserelin implant is a pre-filled syringe with a very large (16G) needle; always warn the patient and consider using a lidocaine/prilocaine cream or local lidocaine injection beforehand. Unlike leuprolide, goserelin has a specific FDA indication for breast cancer. In the adjuvant breast cancer setting (SOFT/TEXT trials), it is used to allow the use of aromatase inhibitors in premenopausal women. If a patient experiences severe abdominal pain after injection, evaluate for abdominal wall…

Related Therapies & Mechanisms

• Abiraterone Acetate (Zytiga) — Hormonal Agent · Prostate
• Anastrozole (Arimidex) — Hormonal Agent · Breast
• Apalutamide (Erleada) — Hormonal Agent · Prostate
• Bicalutamide (Casodex) — Hormonal Agent · Prostate