Buserelin Acetate

What it is and how it works

Buserelin is a synthetic GnRH analogue. After an initial stimulation of LH and FSH release, continuous administration down-regulates pituitary GnRH receptors, suppressing gonadotrophin secretion and reducing testosterone or oestrogen to castrate or post-menopausal levels.

Indications

Advanced hormone-dependent prostate cancer; endometriosis; pituitary down-regulation before ovarian stimulation in assisted reproduction (in vitro fertilisation).

Dosage and administration (summary)

Dose and regimen depend on indication and formulation: for prostate cancer, for example, 500 micrograms by subcutaneous injection every 8 hours for 7 days followed by maintenance intranasal or depot administration; for assisted reproduction, daily subcutaneous doses according to the fertility protocol.

Contraindications

Hormone-independent prostate cancer; after orchidectomy (for prostate cancer); pregnancy and breast-feeding; undiagnosed vaginal bleeding; hypersensitivity to buserelin.

Warnings and precautions

In prostate cancer an initial testosterone surge (tumour flare) may cause bone pain, urinary obstruction or spinal cord compression; an anti-androgen should be given for several days before and during the first weeks of treatment. Long-term use causes loss of bone mineral density, hot flushes, decreased libido and mood changes, and may increase cardiovascular and diabetes risk. In fertility treatment, monitor for ovarian hyperstimulation syndrome.

Pregnancy

Contraindicated in pregnancy; pregnancy should be excluded before starting treatment.

Storage and supply

Store below 25 °C, protected from light; do not freeze (follow the specific product’s instructions; some presentations require refrigeration).

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.