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Zoladex

Generic name: goserelin (implant) [ GOE-se-REL-in ]
Drug classes: Gonadotropin releasing hormones, Hormones / antineoplastics

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jun 2, 2023.

What is Zoladex?

Zoladex is a man-made form of a hormone that regulates many processes in the body. Goserelin overstimulates the body's own production of certain hormones, which causes that production to shut down temporarily.

Zoladex implants are used to treat symptoms of prostate cancer in men.

The Zoladex implant is used in women to treat breast cancer or endometriosis. Zoladex is also used in women to prepare the lining of the uterus for endometrial ablation (a surgery to correct abnormal uterine bleeding).

Zoladex is sometimes used in combination with another cancer drug called flutamide.

Warnings

Goserelin can harm an unborn baby or cause birth defects. Unless you are being treated for advanced breast cancer, you should not use Zoladex during pregnancy. Use effective non-hormonal (barrier) birth control during treatment and for at least 12 weeks after treatment ends. Tell your doctor right away if you become pregnant during treatment. You should not breast-feed while you are using Zoladex.

You should not use Zoladex if you are allergic to goserelin or to similar hormone medications such as leuprolide (Lupron, Eligard, Viadur), nafarelin (Synarel), or ganirelix (Antagon).

Before you receive Zoladex, tell your doctor if you have osteoporosis, diabetes, urination problems, a condition affecting your spine, a history of heart attack or stroke, risk factors for coronary artery disease (such as high blood pressure, high cholesterol, smoking, or being overweight), or if you have abnormal bleeding that your doctor has not checked.

Zoladex can decrease bone mineral density, which may increase your risk of developing osteoporosis. This risk may be greater if you smoke, drink alcohol frequently, have a family history of osteoporosis, or use certain drugs such as seizure medications or steroids. Talk to your doctor about your individual risk of bone loss.

Call your doctor at once if you have a serious side effect while using Zoladex, such as severe numbness or tingling in your legs or feet, muscle weakness, problems with balance or coordination, loss of bladder or bowel control, urinating less than usual, pain or burning when you urinate, blood in your urine or stools, easy bruising, increased thirst or urination, fruity breath odor, trouble breathing, sudden numbness or weakness, sudden severe headache, confusion, problems with vision or speech, or chest pain spreading to the arm or shoulder

Before taking this medicine

You should not be treated with Zoladex implants if you are allergic to goserelin, or to similar hormone medications such as histrelin, leuprolide, nafarelin, or ganirelix.

This medicine can harm an unborn baby, but goserelin is sometimes used in pregnant women with advanced breast cancer. Unless you are being treated for advanced breast cancer, you should not use Zoladex during pregnancy. You may need to have a negative pregnancy test before starting this treatment.

If you have not gone through menopause, you should use a nonhormonal form of birth control (condom, diaphragm, cervical cap, contraceptive sponge) to prevent pregnancy while the Zoladex implant is in place.

Keep using birth control for at least 12 weeks after the implant was removed. Even though the Zoladex implant can stop ovulation and menstrual periods, you could still become pregnant.

To make sure Zoladex is safe for you, tell your doctor if you have ever had:

Goserelin can decrease bone mineral density, which may increase your risk of developing osteoporosis. This risk may be greater if you smoke, drink alcohol frequently, have a family history of osteoporosis, or use certain drugs such as seizure medicine or steroids. Talk to your doctor about your individual risk.

You should not breastfeed while the implant is in place.

How is Zoladex given?

Zoladex is given in a tiny implant inserted through a needle into the skin of your stomach, once every 28 days. You will receive the implant in a clinic or doctor's office.

Your dosing schedule may be different if you are also receiving chemotherapy. Follow your doctor's instructions. It is very important to receive your Zoladex implant injections on time each month.

You are not likely to be able to feel the implant through your skin, and it should not cause pain or discomfort. The implant will dissolve in your body over time.

While your hormone levels are adjusting, you may notice new or worsening symptoms of your condition during the first few weeks of treatment. Tell your doctor if your symptoms do not improve after several weeks.

If you are a premenopausal woman, you should stop having menstrual periods while the Zoladex implant is in place. Call your doctor if you still have regular periods. Missing a dose can cause breakthrough bleeding. After you stop using Zoladex, you should begin having regular periods within 12 weeks.

Your blood sugar may need to be checked while using Zoladex, even if you are not diabetic.

Goserelin can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using Zoladex.

Dosing information

Usual Adult Dose for Prostate Cancer:

For the palliative treatment of advanced carcinoma of the prostate:
3.6 mg or 10.8 mg subcutaneously into the upper abdominal wall once
The 3.6 mg dosage may be repeated every 28 days.
The 10.8 mg dosage may be repeated every 12 weeks.
Intended for long-term administration unless clinically inappropriate.

Prostate cancer, stage B2 to C (in combination with an antiandrogen and radiotherapy; begin 8 weeks prior to radiotherapy): Males: SubQ:
Combination 28-day/12-week implant: 3.6 mg implant, followed in 28 days by 10.8 mg implant
OR
28-day implant (alternate dosing): 3.6 mg; repeated every 28 days for a total of 4 doses (2 depots preceding and 2 during radiotherapy)

Uses:
-In combination with flutamide for the management of locally confined Stage T2b-T4 (Stage B2-C) carcinoma of the prostate. Treatment should start 8 weeks prior to radiation therapy and continue during radiation.
-For palliative treatment of advanced carcinoma of the prostate.

Usual Adult Dose for Endometriosis:

3.6 mg subcutaneously into the upper abdominal wall once; repeat every 28 days

The recommended duration of therapy is 6 months.

Use: For the management of endometriosis, including pain relief and reduction of endometriotic lesions.

Usual Adult Dose for Breast Cancer--Palliative:

For use in the palliative treatment of advanced breast cancer: 3.6 mg subcutaneously into the upper abdominal wall once; repeat every 28 days

Intended for long-term administration unless clinically inappropriate.

Use: For the palliative treatment of advanced breast cancer in pre- and perimenopausal women

Usual Adult Dose for Bleeding:

1 or 2 of the 3.6 mg subcutaneous depot injections (with each depot given 4 weeks apart). When 1 depot is administered, surgery should be performed at 4 weeks. When 2 depots are administered, surgery should be performed within 2 to 4 weeks following administration of the second depot.

Use: For use as an endometrial-thinning agent prior to endometrial ablation for dysfunctional uterine bleeding.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment to receive your Zoladex implant.

What happens if I overdose?

Since the Zoladex implant contains a specific amount of the medicine, you are not likely to receive an overdose.

What to avoid

Avoid drinking alcohol. It can increase your risk of bone loss while you are being treated with Zoladex.

Avoid smoking, which can increase your risk of bone loss, stroke, or heart problems.

Zoladex side effects

Get emergency medical help if you have signs of an allergic reaction to Zoladex: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

When you start treatment with Zoladex, your tumor symptoms may get worse for a short time. Worsening of a prostate tumor may increase pressure on your spinal cord or urinary tract. Tell your doctor right away if you have symptoms such as: back pain, painful or difficult urination, loss of movement in any part of your body, or loss of bowel or bladder control.

Call your doctor at once if you have:

Common Zoladex side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Zoladex?

Goserelin can cause a serious heart problem. Your risk may be higher if you also use certain other medicines for infections, asthma, heart problems, high blood pressure, depression, mental illness, cancer, malaria, or HIV.

Tell your doctor about all your other medicines, especially a blood thinner (warfarin, Coumadin, Jantoven).

Other drugs may interact with goserelin, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Popular FAQ

Zoladex (goserelin acetate implant) 3.6mg usually stops ovulation and menstruation when used once every 28 days to manage endometriosis or for endometrial thinning prior to endometrial ablation. However, effective non-hormonal contraception is still recommended for premenopausal women during treatment with Zoladex and for 12 weeks after stopping therapy because it is still possible to become pregnant while using Zoladex.

Zoladex (goserelin acetate implant) comes in a ready-to-use syringe that does not need to be kept in the fridge. Zoladex is administered into the anterior abdominal wall below the navel following these six steps:

  1. Clean the injection site with an alcohol swab.
  2. Inspect the foil pouch and syringe for damage, check you can see the implant in the syringe by holding the syringe at a slight angle, and then remove the safety tab and needle cover.
  3. Pinch the skin at the injection site and place the needle on the skin at a 30-45 degree angle with the bevel facing up.
  4. Insert the needle until the protective sleeve touches the patient’s skin. Make sure the bevel is facing upwards and take care to avoid peritoneum or the muscle. If blood appears in the syringe chamber, start over with a new syringe at a new injection site and monitor for signs of abdominal hemorrhage.
  5. Push down on the plunger until you hear the click that indicates the implant has been released.
  6. Remove the syringe for the skin, allowing the protective sleeve to cover the needle, then dispose of the syringe in a sharps container.

Zoladex (goserelin acetate implant) can cause alopecia or hair loss. Alopecia is a common (≥ 1% and < 10%) side effect in females. Mild hair loss on the head has been reported in females treated with Zoladex, although in some cases it can be severe. Younger patients, including those treated for benign conditions may experience this type of hair loss. Zoladex can also cause alopecia in male patients, although it’s unclear how frequently this occurs. Zoladex tends to result in a loss of body hair in males because it lowers androgen levels.

Zoladex (goserelin acetate implant) can cause weight gain in certain patients. In clinical trials, weight increases were observed in greater than 1%, but less than 5% of prostate cancer patients treated with Zoladex 10.8mg every 12 weeks. Treatment with Zoladex 3.6mg also resulted in weight gain in greater than 1%, but less than 5% of prostate cancer patients. In addition, weight gain was observed in 3% of patients with endometriosis who received Zoladex 3.6mg every 28 days.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Zoladex only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.