ZOLADEX 10.8 (GOSERELIN 10.8MG) – DEPOT INJECTION

Description

Uses and Administration of Zoladex in Kenya

Goserelin/Zoladex is an analogue of gonadorelin with similar properties. It is used for the suppression of gonadal 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 approximately equivalent to 10 mg of goserelin.

Goserelin acetate is available in Kenya as a depot preparation; 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 concomitant 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 employed.

In the treatment of prostatic cancer an anti-androgen such as cyproterone acetate may be given for several days before beginning goserelin/Zoladex therapy and continued for at least 3 weeks, to avoid the risk of a disease flare.

Regimens for oocyte collection for in-vitro fertilisation in Kenya employ 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gonadotrophin (follicle stimulating) therapy is begun until an appropriate stage of follicular development, when it is withdrawn and chorionic gonadotrophin is given to induce ovulation.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.

Endometriosis.

Gonadorelin analogues such as Zoladex 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.

Adverse Effects of Zoladex in Kenya

Gonadorelin and its analogues are generally well tolerated but may cause gastrointestinal adverse effects, usually nausea and abdominal pain or discomfort. There may be headache or lightheadedness, and an increase in menstrual bleeding.

Continued therapy with gonadorelin analogues results in paradoxical suppression of the pituitary gonadal axis; in premenopausal women this may produce menopausal symptoms, including vaginal dryness, hot flushes, and loss of libido. If sufficiently prolonged the suppression of circulating oestrogens may lead to osteoporosis.

In men, hot flushes and sexual dysfunction have occurred. Breast swelling and tenderness in men have been reported infrequently with gonadorelin analogues. Other adverse effects reportedly associated with gonadorelin analogue therapy, and presumably related to changes in the hormonal milieu, include mood changes, nervousness, palpitations, acne and dry skin, alterations in liver function tests and blood lipids, decreased glucose tolerance, and changes in scalp and body hair.

Ovarian hyperstimulation, although rare, has occurred in women given gonadorelin.