Zoladex vs. Eligard

Zoladex 10.8 (goserelin acetate implant) and Eligard (leuprolide acetate) are man-made forms of hormones used in men to treat symptoms of prostate cancer, and in women to treat endometriosis.

Zoladex 10.8 is also used in women to treat breast cancer or to prepare the lining of the uterus for endometrial ablation (a surgery to correct abnormal uterine bleeding).

Eligard is also used in women to treat symptoms of uterine fibroids, and to treat precocious (early-onset) puberty in both male and female children.

Side effects of Zoladex and Eligard that are similar include hot flashes, flushing, dizziness, increased sweating, changes in sexual interest, impotence, sleep problems (insomnia), nausea, breast swelling or tenderness, vaginal dryness/itching/discharge, mental/mood changes (such as depression, mood swings, hallucinations), injection site reactions (pain, bruising, bleeding, redness, stinging, burning, or swelling), diarrhea, constipation, acne, and itching.

Side effects of Zoladex that are different from Eligard include headache, fewer erections than usual, changes in breast size, hair loss, bone pain, and skin rash.

Side effects of Eligard that are different from Zoladex include night sweats, chills, clammy skin, tiredness, swelling of ankles or feet, increased urination at night, increased growth of facial hair, breakthrough bleeding in a female child during the first 2 months of Eligard treatment, weakness, stomach pain, skin redness/scaling, joint or muscle pain, testicle pain, and memory problems.

Both Zoladex and Eligard may interact with antidepressants, antibiotics, drugs to treat malaria, antipsychotic medicines, cancer medicines, and HIV/AIDS medications.

Zoladex may also interact with alcohol and heart rhythm medicines.

Eligard may also interact with antifungal medicines, asthma inhalers, heart or blood pressure medicines, or medicines to prevent vomiting.

Side effects of Zoladex include:

• hot flashes (flushing)
• dizziness
• headache
• increased sweating
• increased or decreased sexual interest
• impotence
• fewer erections than usual
• trouble sleeping
• nausea
• change in breast size
• breast swelling or tenderness
• vaginal dryness/itching/discharge
• hair loss, mental/mood changes (such as depression, mood swings, hallucinations)
• injection site reactions (pain, bruising, bleeding, redness, or swelling)
• bone pain
• diarrhea
• constipation
• sleep problems (insomnia)
• acne, or
• skin rash or itching

Common side effects of Eligard include:

• hot flashes (flushing),
• increased sweating,
• night sweats,
• chills,
• clammy skin,
• tiredness,
• swelling of the ankles or feet,
• increased urination at night,
• mental/mood changes (e.g., depression, mood swings),
• dizziness,
• injection site reactions (redness, stinging, burning, pain, bruising),
• acne,
• increased growth of facial hair,
• breakthrough bleeding in a female child during the first 2 months of Eligard treatment,
• weakness,
• nausea,
• diarrhea,
• constipation,
• stomach pain,
• skin redness/itching/scaling,
• joint or muscle pain,
• vaginal itching or discharge,
• breast swelling or tenderness,
• testicle pain,
• impotence,
• loss of interest in sex,
• sleep problems (insomnia), or
• memory problems.

Tell your doctor if you have serious side effects of Eligard including:

• new or worsening bone pain,
• easily broken bones,
• increased thirst, or
• mental/mood changes (such as depression, thoughts of suicide, mood swings, aggression in children).

Zoladex 10.8 (goserelin acetate implant) is a man-made form of a hormone used in men to treat symptoms of prostate cancer, and in women to treat breast cancer or endometriosis. Zoladex 10.8 is also used in women to prepare the lining of the uterus for endometrial ablation (a surgery to correct abnormal uterine bleeding). Zoladex 10.8 treats only the symptoms of prostate cancer but does not treat the cancer itself.

Other drugs may interact with Eligard. Tell your doctor all prescription and over-the-counter medications and supplements you use. Eligard must not be used during pregnancy. It may harm a fetus. If you become pregnant or think you may be pregnant, inform your doctor. Consult your doctor to discuss birth control. Non-hormonal birth control methods are recommended. It is unknown if this drug passes into breast milk. Because the effects of this drug on a nursing infant are unknown, breastfeeding is not recommended.

There may be other drugs that can interact with Zoladex. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Zoladex is not recommended for use during pregnancy. It may harm a fetus. Women of child-bearing age must not be pregnant when starting this medication. Consult your doctor to discuss use of birth control. For women, this medication should stop the release of an egg (ovulation) and your periods, but this should not be used as a reliable method of birth control. It is recommended that men and women using this medication use 2 forms of non-hormonal birth control (e.g., condoms and diaphragm with spermicide) while taking this medication. Continue using birth control until the return of the woman's period or for at least 12 weeks after stopping this medication. It is not known whether this medication passes into breast milk. Because of the possible risk to the infant, breastfeeding while using this medication is not recommended.

Eligard may interact with cold or allergy medicine, sedatives, narcotics, sleeping pills, muscle relaxers, seizure medications, antidepressants, anxiety medicines, lithium, atropine, belladonna, benztropine, dimenhydrinate, methscopolamine, scopolamine, blood pressure medications, blood thinners, bronchodilators, bladder or urinary medications, MAO inhibitors, medicines to treat Parkinson's disease, restless leg syndrome medications, medicines to treat pituitary gland tumor, or medicines to treat stomach ulcer or irritable bowel syndrome. Tell your doctor all medications and supplements you use. Eligard Tablets and Suppositories should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. It is not known whether Eligard is excreted in human milk. Because of the potential for serious adverse reactions in nursing infants from Eligard Tablets and Suppositories, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

Zoladex, at a dose of 10.8 mg, is administered subcutaneously every 12 weeks under the supervision of a physician. For female patients the 3.6 mg implant is used.

Eligard is administered subcutaneously and provides continuous release of leuprolide acetate over a one-, three-, four-, or six-month treatment period, depending on the dose.