(British Approved Name, US Adopted Name, rINN)
International Nonproprietary Names (INNs) in main languages (French, Latin, Russian, and Spanish):
Pharmacopoeias. In Europe.
European Pharmacopoeia, 6th ed. (Goserelin). A nonapeptide analogue of the hypothalamic decapeptide, gonadorelin. It is obtained by chemical synthesis and is available as an acetate. A white or almost white powder. Soluble in water freely soluble in glacial acetic acid. It dissolves in dilute solutions of mineral acids and alkali hydroxides. Store at 2° to 8° in airtight containers. Protect from light.
(British Approved Name Modified, rINNM)
International Nonproprietary Names (INNs) in main languages (French, Latin, and Spanish):
Adverse Effects and Precautions
As for Gonadorelin. Some women may have vaginal bleeding during initial therapy, which normally resolves spontaneously.
Pituitary apoplexy (a clinical syndrome caused by haemorrhage and infarction of a pituitary adenoma) occurred in a few elderly patients with a symptomless pituitary adenoma who were given goserelin for advanced prostate cancer. Symptoms included headache, vomiting, visual disturbances, gradual impairment of consciousness, intermittent fever, and progressive hyponatraemia. Symptoms were treated with corticosteroid replacement therapy.
Goserelin is almost completely absorbed after subcutaneous injection, and has a serum elimination half-life of 2 to 4 hours, which may be increased in renal impairment. More than 90% of a dose is excreted in urine, as unchanged drug and metabolites.
Uses and Administration
Goserelin is an analogue of gonadorelin with similar properties. It is used for the suppression of go-nadal sex hormone production in the treatment of malignant neoplasms of the prostate, in breast cancer in pre- and peri-menopausal women, and in the management of endometriosis and uterine fibroids. It is also given before surgery for endometrial reduction and as an adjunct to ovulation induction with gonadotrophins in the treatment of infertility. Goserelin is usually given as the acetate but doses are expressed in terms of the base 10.5 mg of goserelin acetate is equivalent to about 10 mg of goserelin.
Goserelin acetate is available as depot preparations with one such preparation a dose equivalent to 3.6 mg of goserelin injected subcutaneously into the anterior abdominal wall provides effective suppression of oestradiol or testosterone for 28 days. A full response should be achieved by the end of this period and treatment is continued with repeated doses at 28-day intervals in endometriosis, therapy is given for up to 6 months, while in women with anaemia as a result of uterine fibroids it is continued, with iron supplementation, for up to 3 months before surgery. In men with prostate cancer, preparations supplying the equivalent of 10.8 mg of goserelin, given every 12 weeks, may also be used.
In the treatment of prostatic cancer an anti-androgen such as cyproterone acetate may be given for several days before beginning goserelin therapy and continued for at least 3 weeks, to avoid the risk of a disease flare.
Regimens for oocyte collection for IVF use gonadorelin analogues for pituitary desensitisation before ovulation induction with gonadotrophins. The equivalent of 3.6 mg of goserelin is given as a subcutaneous depot injection and serum-oestradiol concentrations monitored until they decline to levels similar to those in the early follicular phase, a process which usually takes 7 to 21 days. Once downregulation occurs gonadotrophin (follicle stimulating) therapy is begun until an appropriate stage of follicular development, when it is withdrawn and chorionic gonadotrophin is given to induce ovulation.
Goserelin has also been given in other sex-hormone-related conditions.
Gonadorelin analogues such as goserelin are effective in the management of endometriosis, but the need for long-term therapy to prevent recurrence limits their value because of the risk of osteoporosis. ‘Add-back’ therapy, with concomitant hormone replacement, may be given in an attempt to reduce bone mineral density loss and vasomotor symptoms in women receiving goserelin. References.
Gonadorelin analogues such as goserelin have been tried as an adjunct or an alternative to surgery in the treatment of uterine fibroids although there has been some concern that this might complicate the diagnosis of malignancy. Some further references are listed below.
Goserelin is effective in the treatment of prostate cancer. It has produced a response similar to that of orchidectomy (surgical removal of the testes) in patients with metastatic prostate cancer. Goserelin has been combined with an anti-androgen such as flutamide to provide maximum androgen blockade, but this appears to produce modest additional benefits at most. There is some evidence that adjuvant therapy with goserelin may improve survival in patients with localised or locally advanced prostate cancer when combined with radiotherapy or radical prostatectomy, and adjuvant use of goserelin appears to be more beneficial than neoadjuvant use. Goserelin may also be used as hormonal therapy in premenopausal women with advanced breast cancer it seems to be as effective as oophorectomy, and use with tamoxifen is more effective than goserelin alone. It is also used as an alternative or addition to adjuvant chemotherapy in pre- or peri-menopausal women with oestrogen-receptor positive early breast cancer.
For reference to the use of goserelin in mastalgia, see under Danazol.
For reference to the use of goserelin or other gonadorelin analogues (with HRT to prevent menopausal symptoms) in women unresponsive to other drug treatment, see under Gonadorelin.
Argentina: Larmadex Zoladex
Chile: Vacromil Zoladex
Czech Republic: Zoladex
Hong Kong: Zoladex
New Zealand: Zoladex
South Africa: Zoladex
Australia: Zolacos CR