gonadotropin-releasing hormone analogue
- Goserelin (3.6 mg pellet) is injected under the skin of the
abdomen (subcutaneously) once every 28 days. The pellet is gradually absorbed
by the body.
- Leuprolide is injected into a muscle
(intramuscularly) once a month. It is also available in a dose that lasts for 3
- Nafarelin is sprayed into the nose (intranasally) twice a
Gonadotropin-releasing hormone analogue (GnRH-a) therapy
is approved for the treatment of endometriosis and
uterine fibroids. A GnRH-a is rarely used for
abnormal uterine bleeding.
To avoid long-term side effects, GnRH-a therapy is usually taken for only 3 to 6 months.
How It Works
GnRH-a therapy decreases the production
of the hormone
estrogen to the levels that women have after
menopause. This decrease:
ovulation and stops menstrual periods (but it does not
provide dependable pregnancy prevention).
- Stops the growth of and
reduces the size of endometriosis sites (implants).
- Reduces uterine
- Stops uterine fibroid growth and promotes fibroid
Why It Is Used
GnRH-a therapy is used to help
diagnose or treat disorders that are linked to menstrual hormones, such as
endometriosis and uterine fibroids. GnRH-a therapy may be used:
- For abnormal uterine bleeding or
- When an
ultrasound has confirmed that uterine fibroids are
present and they cause significant symptoms.
Abnormal uterine bleeding.
GnRH-a therapy is used under special circumstances, such as when no other
medical treatment has reduced uterine bleeding and a woman wants to avoid
GnRH-a therapy is sometimes used to thin the
endometrial ablation for abnormal uterine
a good choice for women who have heavy menstrual periods after organ transplant
procedures, especially a liver transplant. If it is used for long-term
therapy after organ transplant, then additional treatment with daily estrogen
progesterone is recommended to prevent bone loss
(osteoporosis). This is
called "add-back" therapy.
Uterine fibroids. GnRH-a therapy is usually limited to
presurgery treatment to:
- Shrink fibroids before removal by
anemia caused by heavy bleeding. (Iron supplements are
another option for correcting anemia.)
GnRH-a therapy is not usually used to relieve fibroid
symptoms only, because fibroids grow back fairly quickly after GnRH-a therapy
ends. But for women who are close to menopause (when fibroids shrink),
short-term relief with GnRH-a therapy may be a reasonable option.
Before gynecologic surgery. GnRH-a
therapy may be used before surgery to:1
- Reduce the size of fibroids or endometriosis
sites (implants). This allows for easier removal of the problem growths or the
- Attempt to prevent scarring that might occur
GnRH-a therapy is usually used for short periods of time (3
to 6 months).
It can weaken the bones when used for longer periods
How Well It Works
Abnormal uterine bleeding. GnRH-a therapy causes a significant reduction in severe
menstrual bleeding. This relieves anemia and reduces the need for
blood transfusions. But blood loss returns to
pretreatment levels when this treatment is stopped.
Uterine fibroids. Fibroids usually shrink to 35% to
65% of their original size.1
- Smaller fibroids are easier to remove
- Smaller fibroids result in fewer surgical
complications and less blood loss during surgery.
- Small fibroids
may completely disappear after 12 weeks of treatment.
- A vaginal
hysterectomy may be possible, which would avoid an abdominal
Ovarian cysts. GnRH-a therapy may
reduce or prevent ovarian cysts that are related to ovulation.
Chronic pelvic pain. Women report improvement in
pelvic pain at the end of treatment with:
- Leuprolide (Lupron
- Nafarelin (Synarel).
- These medicines are only a temporary
solution. When treatment stops, chronic pelvic pain and fibroid growth will
gradually return until menopause.
All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.
Here are some important things to think about:
- Usually the benefits of the medicine are more important than any minor side effects.
- Side effects may go away after you take the medicine for a while.
- If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.
Call911or other emergency services right away if you have:
Call your doctor if you have:
Common side effects of this medicine include:
See Drug Reference for a full list of side
effects. (Drug Reference is not available in all systems.)
What To Think About
Many doctors are prescribing GnRH-a therapy in combination with other medicines such as low-dose estrogen and progestin to control bone-thinning and decrease menopausal side effects, such as hot flashes. Add-back therapy is usually started if you need to be on GnRH-a therapy for more than 3 to 6 months.
Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.
There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.
Advice for women
Do not use this medicine if you are pregnant, breast-feeding, or planning to get pregnant. If you need to use this medicine, talk to your doctor about how you can prevent pregnancy.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.
Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.
American College of Obstetricians and
Gynecologists (2008, reaffirmed 2012). Alternatives to hysterectomy in the management of
leiomyomas. ACOG Practice Bulletin No. 96. Obstetrics and Gynecology, 112(2, Part 1): 387–399.
Primary Medical Reviewer
||Sarah Marshall, MD - Family Medicine
Specialist Medical Reviewer
||Divya Gupta, MD - Obstetrics and Gynecology, Gynecologic Oncology
Current as of
||March 12, 2014