LH-RH Agonists/GnRH Agonists for Prostate Cancer

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LH-RH Agonists/GnRH Agonists for Prostate Cancer


Generic NameBrand Name
histrelinSupprelin La, Vantas
leuprolideEligard, Lupron

How It Works

Luteinizing hormone-releasing hormone (LH-RH) agonists and gonadotropin-releasing hormone (GnRH) agonists are hormone therapy drugs that lower the production of testosterone in a man's body. This drop in testosterone usually slows or stops the growth of prostate cancer for a period of time.

These drugs work by causing the pituitary gland to release the hormones that cause the testicles and adrenal glands to make testosterone. The pituitary gland then runs out of its hormones, and testosterone production drops.

These drugs are usually given by injection or implanted under the skin. They may be given once a month, once every 3 to 4 months, or once a year.

Why It Is Used

LH-RH and GnRH agonists are used to treat advanced prostate cancer. They are often used with other treatments, such as surgery or radiation therapy.

LH-RH and GnRH agonist therapy can also be used to relieve pain caused by metastatic prostate cancer.

How Well It Works

LH-RH agonist therapy improves a man's chances of living longer. When combined with radiation therapy or surgery to remove the prostate, LH-RH therapy may improve survival in men who have locally advanced cancer.

Treatment with LH-RH agonists may control severe pain caused by metastatic prostate cancer and may improve a man's quality of life. If treatment is started as soon as cancer progression is evident, LH-RH agonists may be able to reduce bone fractures and spinal cord compression caused by metastatic disease.1

Side Effects

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.

Call 911 or other emergency services right away if you have:

  • Trouble breathing.
  • Swelling of your face, lips, tongue, or throat.
  • Shortness of breath and chest pain.

Call your doctor if you have:

  • Hives.
  • Breast pain or breast enlargement (gynecomastia).
  • Swelling in your legs, ankles, or feet (edema).

Common side effects of this medicine include:

  • Hot flashes.
  • Sexual problems, such as decreased sex drive or erection problems.
  • Constipation.
  • Fatigue or weakness.
  • Weight gain.
  • Headache.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Hot flashes are a problem with hormone therapy. Hot flashes may last for years. Talk with your doctor about medicines and treatments that may help.

These drugs work on the pituitary gland to release its hormones. So the testicles may temporarily produce extra testosterone, causing a temporary growth in the tumor. This is called a tumor flare. Tumor flare may be accompanied by bone pain, urinary blockage, or other symptoms of rapid cancer growth. This may mean that the drug is working. And although the tumor may grow at first, it will shrink over time. Tumor flare can be prevented by taking a different hormone drug called an antiandrogen before or during treatment with the LH-RH agonist.

Taking medicine

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.


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.



  1. National Cancer Institute (2012). Prostate Cancer Treatment (PDQ)—Health Professional Version. Available online: http://www.cancer.gov/cancertopics/pdq/treatment/prostate/HealthProfessional.


ByHealthwise Staff
Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine
Specialist Medical ReviewerChristopher G. Wood, MD, FACS - Urology, Oncology
Last RevisedSeptember 12, 2012

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