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Goserelin Acetate (Zoladex®) - For Women

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OncoLink
Last Modified: August 22, 2011

Pronounced: GO-suh-REH-lin ASS-uh-TATE
Classification: Gonadotropin-Releasing Hormone Analog

About Goserelin Acetate

While estrogen and progesterone may not actually cause breast cancer, they are necessary for the cancer to grow in some breast cancers. Estrogen and progesterone are female hormones produced by the ovaries. The production of these hormones can be stopped by surgically removing the ovaries or through medication therapy. A hormone called luteinizing hormone, which is produced by the pituitary gland, stimulates production of estrogen and progesterone by the ovaries. LHRH agonists stop the production of luteinizing hormone by the pituitary gland. This reduces the production of estrogen and progesterone. The cancer cells may then grow more slowly or stop growing altogether. Goserelin acetate is a type of LHRH agonist.

How to Take Goserelin Acetate

Goserelin acetate is given as a subcutaneous (under the skin) injection every 4 weeks. There is also a long acting formulation (called depot or implant), which is given every 28 days.

Possible Side Effects of Goserelin Acetate

There are a number of things you can do to manage the side effects of Goserelin Acetate. Talk to your doctor or nurse about these recommendations. They can help you decide what will work best for you. These are some of the most common side effects:

Initial Tumor Flare

When starting goserelin, the body has a temporary increase in estrogen levels. This "flare" can lead to a temporary increase in the tumor size, causing symptoms to worsen. Your healthcare team can tell you what to look for in your particular case and what to do about it.

Sexual and Reproductive Changes

The decrease in estrogen levels can cause a women's menstrual period to stop while taking this medication. Menstruation may or may not return after the medication is stopped, depending on how close the woman was to natural menopause when starting the medication. Women may experience menopausal effects including hot flashes and vaginal dryness - read more about coping with vaginal dryness. In addition, the desire for sex may decrease during treatment.

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective birth control is necessary during treatment, even if your menstrual cycle stops. See OncoLink's section on sexuality for helpful tips for dealing with these side effects.

Hot Flashes

There are a few of things you can do to help hot flashes. Several medications have been studied, including clonidine (a blood pressure medication), some low dose antidepressants (such as venlafaxine and Prozac), and gabapentin. Non-medical recommendations include: keeping well hydrated with 8 glasses of water daily, wearing all-natural fiber clothes, dressing in layers, exercising on a regular basis (generally walking exercise is best), practicing relaxation exercises, and avoiding triggers such as warm rooms, spicy foods, caffeinated beverages, and alcohol.

Osteoporosis

The lack of estrogen while taking LHRH agonists can lead to a weakening of the bones. Your doctor will check your bone health before starting therapy. This is done with a bone density scan (dexa scan). If the scan shows that you already have some bone weakening, your doctor may order a type of medication called a bisphosphonate or calcium and vitamin D supplements to help strengthen the bones. These therapies have been shown to protect the bones from bone loss in women taking aromatase inhibitors. If the bone density remains stable, scans can then be done every two years. Learn more about bone health after cancer therapy.

Bone Pain or Headache

Your doctor or nurse can recommend medication and other strategies to relieve bone pain or headaches.

Fatigue

While on cancer treatment you may need to adjust your schedule to manage fatigue. Plan times to rest during the day and conserve energy for more important activities. Exercise can help combat fatigue; a simple daily walk with a friend can help. Talk to your healthcare team and see OncoLink's section on fatigue for helpful tips on dealing with this side effect.

Other Side Effects

Some women experience weight gain, for which exercise and dietary changes may be helpful. There have been reports of heart problems, including heart failure, arrhythmias and heart attack.