ZOLADEX

What it is

ZOLADEX is a goserelin 10.8 mg implant containing goserelin acetate. It is a sterile white to cream coloured cylindrical sustained release implant in which goserelin acetate is dispersed in a polyglactin co-polymer biodegradable matrix, supplied in a single dose syringe applicator. The SafeSystem incorporates a protective needle sleeve that automatically locks in place following administration of the implant to aid in the prevention of needle stick injury. Goserelin acetate is a GnRH agonist (also known as LHRH agonist) and a potent synthetic decapeptide analogue of LHRH. Following chronic administration, goserelin acetate is a potent inhibitor of gonadotrophin production resulting in gonadal suppression and consequently sex organ regression.

Approved indications

— Palliative treatment of metastatic (M+) or locally advanced prostate cancer where suitable for hormonal manipulation. — Adjuvant and neoadjuvant therapy in combination with radiotherapy for the management of locally advanced prostate cancer in men suitable for hormonal manipulation.

Dosing overview

One implant of ZOLADEX 10.8 mg is injected subcutaneously into the anterior abdominal wall every 3 months. Adjuvant and/or neoadjuvant ZOLADEX therapy in combination with radiotherapy may include short-term use of an anti-androgen to prevent flare.

Key safety warnings

Injection site injury has been reported with ZOLADEX, including events of pain, haematoma, haemorrhage and vascular injury. In very rare cases, administration error resulted in vascular injury and haemorrhagic shock requiring blood transfusions and surgical intervention. Extra care should be taken when administering ZOLADEX to patients with a low BMI and/or receiving full anticoagulation medications. Initially ZOLADEX, like other GnRH agonists, transiently increases serum testosterone. There have been reports of temporary increase in bone pain in patients with advanced cancer and bony metastases, which may last up to two weeks and may need to be managed symptomatically. The use of ZOLADEX in patients with metastatic cancer who are at particular risk of developing ureteric obstruction or spinal cord compression should be considered carefully and the patients monitored closely during the first month of therapy. If spinal cord compression or renal impairment due to ureteric obstruction are present or develop, specific standard treatment of these complications should be instituted. ZOLADEX causes loss of bone mineral density. Hyperglycaemia and an increased risk of developing diabetes have been reported in men receiving GnRH agonists. Hyperglycaemia may represent development of diabetes mellitus or worsening of glycaemic control in patients with diabetes. Blood glucose and/or glycosylated haemoglobin (HbA1c) should be monitored periodically. An increased risk of developing myocardial infarction, sudden cardiac death and stroke has been reported in association with use of GnRH agonists in men. The risk appears low based on the reported odds ratios and should be evaluated carefully along with cardiovascular risk factors when determining treatment for patients with prostate cancer. Androgen deprivation therapy may prolong QT/QTc interval. Prescribers should consider whether the benefits of androgen deprivation therapy outweigh the potential risks in patients with congenital long QT syndrome, congestive heart failure, frequent electrolyte abnormalities and in patients taking drugs known to prolong the QT interval.

Contraindications

ZOLADEX is contraindicated in patients with known hypersensitivity to Luteinising Hormone Releasing Hormone (LHRH), LHRH agonist analogues or any of the components of ZOLADEX.

PBS listing

ZOLADEX 10.8 mg subcutaneous implant (long acting) in pre-filled injection syringe is listed on the PBS as one restricted item with an ex-manufacturer price of A$625.45.

Regulatory history

ZOLADEX 10.8 mg implant was first listed on the ARTG on 22 May 1996.