Goserelin Acetate (Zoladex®) - For Women
Last Modified: November 23, 2015
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 (SQ, under the skin) injection every 4 weeks. There is also a long acting formulation (called depot or implant), which is given every 4 months.
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.
There are a few things you can do to help with hot flashes. Several medications have been shown to help with symptoms, including clonidine (a blood pressure medication), low doses of certain antidepressants (such as venlafaxine and Prozac), and gabapentin. Non-medical recommendations include:
- Keep well-hydrated with eight glasses of water daily.
- Drink ice water or apply an ice pack at the onset of a hot flash.
- Wear cotton or lightweight, breathable fabrics and dress in layers so you can adjust as needed.
- Exercise on a regular basis.
- Try practicing meditation or relaxation exercises to manage stress, which can be a trigger.
- Avoid triggers such as warm rooms, spicy foods, caffeinated beverages, and alcohol.
Injection Site Irritation
This medication can cause irritation and injury at the site of injection, including pain, bruising, or bleeding. Contact your care provider if you develop abdominal pain, abdominal distension, shortness of breath, dizziness or if you are difficult to arouse.
Weakening of the Bones (Osteoporosis)
The lack of estrogen while taking LHRH agonists can lead to a weakening of the bones (osteoporosis). This risk is highest for women with other risk factors. You may be advised to take calcium and vitamin D supplements to help prevent bone loss. Weight bearing exercise and a healthy diet rich in calcium and vitamin D can help protect your bone health. You may have a bone density scan (DEXA scan) to assess your bone health. If your physician determines that you are at high risk of developing osteoporosis, they may recommend additional treatment with a type of medication called a bisphosphonate to help strengthen the bones.
Muscle or Joint Pain/Aches
This medication can be associated with joint or muscle aches and pains. If it is bothersome, it may be treated with medications. Be sure to discuss which pain relievers you can safely take with your oncology team, as these are not without their own side effects. Non-medical therapies, such as acupuncture, yoga, gentle stretching and exercise may also help reduce this side effect.
Fatigue is very common during cancer treatment and is an overwhelming feeling of exhaustion that is not usually relieved by rest. While on cancer treatment, and for a period after, 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 for helpful tips on dealing with this side effect.
Vaginal dryness and related painful intercourse is one of the more common side effects of cancer therapy in women. Vaginal lubricants and moisturizers (longer lasting form of moisturizers) can help with these concerns. Talk to your healthcare team for more suggestions in managing this side effect.
Other Side Effects
Some patients taking this medication report headaches, increased mood swings and depression.
Nausea and/or Vomiting
Talk to your doctor or nurse so they can prescribe medications to help you manage nausea and vomiting. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try antacids, (e.g. milk of magnesia, calcium tablets such as Tums), saltines, or ginger ale to lessen symptoms.
Sexual and Reproductive Concerns
This drug will affect your reproductive system, resulting in the menstrual cycle stopping. If your menstrual cycle continues or you experience spotting, you should notify your care provider. Menstruation often resumes after the therapy is stopped. Women may experience menopausal effects, including decreased libido (interest in sex), hot flashes, and vaginal dryness.
Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant while on this medication. Non-hormonal methods of birth control (condoms, spermicide, diaphragm, Paraguard, IUD) are necessary during treatment and for at least 12 weeks after treatment. You may want to consider egg harvesting if you may wish to have a child in the future. Discuss these options with your oncology team.