Zoladex

Question 1

What are the therapeutic indications of Zoladex

Answer 1

(i) Treatment of prostate cancer in the following settings:
* In the treatment of metastatic prostate cancer where Zoladex has demonstrated comparable survival benefits to surgical castrations
* In the treatment of locally advanced prostate cancer, as an alternative to surgical castration where Zoladex has demonstrated comparable survival benefits to an anti-androgen
* As adjuvant treatment to radiotherapy in patients with high-risk localised or locally advanced prostate cancer where Zoladex has demonstrated improved disease-free survival and overall survival
* As neo-adjuvant treatment prior to radiotherapy in patients with high-risk localised or locally advanced prostate cancer where Zoladex has demonstrated improved disease-free survival
* As adjuvant treatment to radical prostatectomy in patients with locally advanced prostate cancer at high risk of disease progression where Zoladex has demonstrated improved disease-free survival
(ii) Advanced breast cancer in pre and perimenopausal women suitable for hormonal manipulation.
(iii) Zoladex 3.6 mg is indicated in the management of oestrogen receptor (ER) positive early and advanced breast cancer in pre and peri menopausal women.
(iv) Endometriosis: In the management of endometriosis, Zoladex alleviates symptoms, including pain, and reduces the size and number of endometrial lesions.
(v) Endometrial thinning: Zoladex is indicated for the prethinning of the uterine endometrium prior to endometrial ablation or resection.
(vi) Uterine fibroids: In conjunction with iron therapy in the haematological improvement of anaemic patients with fibroids prior to surgery.
(vii) Assisted reproduction: Pituitary downregulation in preparation for superovulation.

Question 2

What are the contraindications of Zoladex

Answer 2

Hypersensitivity to the active substance or to any of the excipients.

Pregnancy and lactation.

Question 3

What are the Pharmacodynamic properties of Zoladex

Answer 3

Zoladex (D-Ser(But)6 Azgly10 LHRH) is a synthetic analogue of naturally occurring LHRH. On chronic administration Zoladex results in inhibition of pituitary LH secretion leading to a fall in serum testosterone concentrations in males and serum estradiol concentrations in females. This effect is reversible on discontinuation of therapy. Initially, Zoladex, like other LHRH agonists, may transiently increase serum testosterone concentration in men and serum estradiol concentration in women.

Question 4

What are the Pharmacokinetic properties of Zoladex

Answer 4

The bioavailability of Zoladex is almost complete. Administration of a depot every four weeks ensures that effective concentrations are maintained with no tissue accumulations. Zoladex is poorly protein bound and has a serum elimination half-life of two to four hours in subjects with normal renal function. The half-life is increased in patients with impaired renal function. For the compound given monthly in a depot formulation, this change will have minimal effect. Hence, no change in dosing is necessary in these patients. There is no significant change in pharmacokinetics in patients with hepatic failure.