Zoladex^® (Capsules) Instructions for Use

ATC Code

L02AE03 (Goserelin)

Active Substance

Goserelin (Rec.INN registered by WHO)

Clinical-Pharmacological Group

Gonadotropin-releasing hormone analogue – depot form

Pharmacotherapeutic Group

Antineoplastic agent, gonadotropin-releasing hormone analog

Pharmacological Action

A synthetic analogue of natural GnRH. With continuous use, it inhibits the pituitary gland’s release of LH and FSH, leading to a decrease in the blood concentrations of testosterone in men and estradiol in women. A temporary increase in the concentrations of these hormones is possible at the beginning of treatment.

By approximately the 21st day after the first depot injection, hormone concentrations decrease: in men – to castration levels; in women – to levels comparable to those observed in the postmenopausal period. Hormone concentrations remain suppressed with continuous treatment.

In this case, most men experience regression of the prostate tumor and symptomatic improvement; in women – a positive response in hormone-dependent forms of breast cancer, endometriosis, and uterine fibroids.

Pharmacokinetics

When using the depot form (3.6 mg), absorption in the first 8 days after administration is slower than in subsequent days (with an interval between injections of 28 days). The C_max in blood plasma is 2.5 ng/ml. The T_1/2 is 4.2 hours.

In patients with severe renal impairment, the T_1/2 is somewhat prolonged (no dose adjustment is required in this case).

Indications

Hormone-sensitive prostate cancer (including as part of combination therapy with bicalutamide); breast cancer (in premenopausal and menopausal periods). Endometriosis; uterine fibroids (as an auxiliary agent in combination with surgical treatment).

ICD codes

Dosage Regimen

Capsules

It is used as a depot form of 3.6 mg every 28 days or 10.8 mg every 12 weeks. Treatment of benign gynecological diseases should be carried out for only 6 months. Repeated courses are not recommended due to the risk of developing loss of some mineral components and decreased bone density.

It is administered subcutaneously into the anterior abdominal wall. If necessary, local anesthesia can be performed.

No dose adjustment is required when used in patients with impaired renal or hepatic function, or in the elderly.

Adverse Reactions

In men: hot flashes and decreased potency; rarely – swelling and tenderness of the mammary glands; at the beginning of treatment – temporary increase in bone pain; in some cases – impaired ureteral patency and spinal cord compression.

In women: hot flashes, increased sweating, and changes in libido, headaches, depression, dryness of the vaginal mucosa; at the beginning of treatment, a temporary worsening of disease symptoms is possible; rarely – change in breast size, demineralization of bone tissue, irreversible menopause.

In both men and women, skin rash is possible; rarely, in patients with bone metastases after the start of therapy, hypercalcemia may occur.

Contraindications

Pregnancy, lactation, childhood, hypersensitivity to goserelin or other GnRH analogues.

Use in Pregnancy and Lactation

Goserelin is contraindicated for use during pregnancy and lactation.

When using goserelin for the treatment of gynecological pathology in women of childbearing age, possible pregnancy should be excluded before starting treatment; during therapy, non-hormonal methods of contraception should be used until menstruation resumes.

Use in Hepatic Impairment

No dose adjustment is required when used in patients with impaired hepatic function.

Use in Renal Impairment

No dose adjustment is required when used in patients with impaired renal function.

Pediatric Use

Contraindicated in childhood.

Geriatric Use

No dose adjustment is required when used in elderly patients.

Special Precautions

Goserelin 10.8 mg is not indicated for use in women.

Goserelin should be used with caution in men at high risk of developing ureteral obstruction or spinal cord compression. In this case, strict medical supervision is necessary during the first month of therapy.

Changes in blood pressure are noted during the use of goserelin.

Goserelin 3.6 mg is also used for pituitary desensitization in preparation for superovulation stimulation as part of an in vitro fertilization program.

Drug Interactions

Drug interactions of goserelin have not been described.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.