Zoladex Injection: Uses, Dosage, Side Effects, Precautions and Alternates

Quick overview

Zoladex Injection contains goserelin (goserelin acetate), a gonadotropin-releasing hormone (GnRH) agonist. It is a small implant placed under the skin of the stomach area by a doctor or nurse, used to treat certain prostate and breast cancers, endometriosis, abnormal uterine bleeding, and uterine fibroids before surgery. It works by lowering the body's sex hormone levels. There is no generic version available.

What is Zoladex Injection

Zoladex is a brand-name prescription medicine that contains goserelin. It is a small implant, about the size of a grain of rice, that is placed under the skin of your stomach area by a doctor or nurse. There is no generic version available.

Zoladex Injection uses

• Certain types of prostate cancer in men
• Endometriosis in women
• Abnormal (dysfunctional) uterine bleeding, including preparing the uterus lining before endometrial ablation surgery
• Advanced or early-stage hormone receptor-positive breast cancer in women
• Uterine fibroids (before surgery)

Benefits of Zoladex Injection

• Can reduce pain and other symptoms of endometriosis
• Can shrink patches of endometriosis tissue and fibroids
• Helps slow or control the growth of certain prostate and breast cancers
• Can reduce heavy or abnormal uterine bleeding before surgery

How Zoladex Injection works

Zoladex lowers the amount of sex hormones (testosterone in men, estrogen in women) made by the body. Because some cancers and conditions like endometriosis depend on these hormones, reducing hormone levels can slow cancer growth and ease symptoms.

Zoladex Injection dosage

Zoladex is given as an implant injected under the skin of the stomach area by a healthcare professional; you do not give it to yourself. You will not usually be able to feel the implant through your skin, and it should not cause ongoing pain or discomfort. It is important to receive each injection on time according to your schedule, and you should keep all your scheduled appointments, since missing or delaying a dose may cause the treatment to not work as well.

You may notice your symptoms get worse for a short time in the first few weeks of treatment while your hormone levels adjust; tell your doctor if symptoms do not improve after several weeks. Women may still have a period in the first couple of weeks after the first injection, but periods should stop after that while on treatment; tell your doctor if regular periods continue. Zoladex is not meant for use in children.

Available forms and strengths

• Injection (implant), 3.6 mg

Side effects of Zoladex Injection

Common

• Hot flashes and sweating
• Headache
• Acne or mild skin rash/itching
• Mood swings or depression
• Decreased sex drive or changes in sexual interest
• Problems getting or keeping an erection (in men)
• Painful urination
• Vaginal dryness, itching, or discharge (in women)
• Changes in breast size or breast shrinkage
• Swelling in hands, feet, arms, or legs (fluid retention)
• Hair loss
• Weight gain
• Kidney or bladder infection

Serious

• Signs of a severe allergic reaction: hives, difficulty breathing, swelling of face/lips/tongue/throat
• Tumor flare - worsening cancer symptoms or new back pain, painful or difficult urination, loss of movement, loss of bowel or bladder control in the first weeks of treatment
• High blood sugar symptoms - increased thirst, increased urination, dry mouth, fruity breath odor
• High calcium levels - confusion, tiredness, nausea, vomiting, loss of appetite, constipation, increased thirst or urination, weight loss
• Heart attack symptoms - chest pain or pressure, pain spreading to jaw/shoulder/arm, nausea, sweating
• Signs of a blood clot or stroke - sudden numbness or weakness on one side of the body, problems with vision or speech, chest pain, leg pain or swelling
• Abnormal heart rhythm - fainting, fast or skipping heartbeat
• Severe injection site reactions - pain, bruising, bleeding, swelling, redness, or oozing where the implant was placed
• Severe skin reactions - fever, flu-like symptoms, mouth/throat/eye blisters, severe or worsening rash, sores or blistering of skin, swollen lymph nodes
• New or worsening thoughts of self-harm or suicide
• Decreased bone mineral density, which may increase the risk of osteoporosis and bone fractures over time

Warnings and precautions

• Tell your doctor before starting Zoladex if you have an irregular heartbeat, heart disease, long QT syndrome, diabetes, or have had an allergic reaction to this or a similar drug.
• Zoladex can lower bone mineral density over time, which may raise the risk of osteoporosis and fractures, even after stopping treatment. This risk may be higher with smoking, frequent alcohol use, or a family history of osteoporosis.
• Zoladex may increase the risk of heart attack or stroke, which can be life-threatening. This risk is higher in people who already have heart disease and increases with longer use or higher doses.
• Zoladex may cause a rare but dangerous heart rhythm problem. People who are older, have a family history of heart rhythm problems, have low potassium or magnesium, or take certain other medicines may be at higher risk.
• When you first start Zoladex, your tumor symptoms may temporarily get worse, a reaction called tumor flare.
• Injuries at the injection site can occur, including pain, bruising, bleeding, and in rare cases serious internal bleeding.
• Zoladex may cause or worsen depression, including thoughts of self-harm.
• Zoladex can harm an unborn baby and should not be used during pregnancy, except in some cases of advanced breast cancer under a doctor's guidance. Tell your doctor right away if you become pregnant during treatment, and use non-hormonal birth control during and for at least 12 weeks after treatment.
• Do not breastfeed while using the Zoladex implant.
• Avoid drinking alcohol, since it can increase the risk of bone loss during Zoladex treatment.
• Zoladex is unlikely to affect your ability to drive or operate machinery.

Storage

• Keep Zoladex in its original packet; only your doctor or nurse should open the seal
• Store in a cool, dry place where the temperature stays below 25°C
• Do not store it in the bathroom or near a sink, and do not leave it in a car or on a windowsill
• Keep it where children cannot reach it; a locked cupboard well above ground level is a good place to store medicines
• Your doctor or nurse will dispose of the syringe and needle after giving you the implant; ask your doctor or pharmacist how to dispose of it if it has passed its expiry date

When to see a doctor

• Get emergency help right away for signs of a severe allergic reaction, such as hives, trouble breathing, or swelling of the face, lips, tongue, or throat.
• Call your doctor right away if you notice signs of tumor flare, such as back pain, painful or difficult urination, loss of movement, or loss of bowel or bladder control.
• Call your doctor immediately if you have symptoms of a heart attack or stroke, such as chest pain, pain spreading to the jaw or arm, sudden numbness or weakness on one side of the body, trouble speaking, or sudden severe headache.
• Contact your doctor immediately if you have abdominal pain, abdominal swelling, shortness of breath, dizziness, low blood pressure, or altered consciousness, which could be signs of a serious injection site injury.
• Call your doctor if you have new or increased thoughts of suicide or self-harm.
• Seek medical help right away if you think you or someone else may have received too much Zoladex.

Alternatives

• Decapeptyl
• Eligard
• Lupron