What you can expect

By Mayo Clinic Staff

LHRH agonist and antagonist medications — also called gonadotropin-releasing hormone (GnRH) agonists and antagonists — stop your body from producing testosterone.

These medications are injected under your skin or into a muscle monthly, every three months or every six months. Or they can be placed as an implant under your skin that slowly releases medication over a longer period of time.

Drugs typically used in this type of hormone therapy include:

  • Leuprolide (Lupron, Eligard)
  • Goserelin (Zoladex)
  • Triptorelin (Trelstar)
  • Histrelin (Vantas)
  • Degarelix (Firmagon)

Testosterone levels may increase briefly (flare) for a few weeks after you receive an LHRH agonist. Anti-androgen medications can help decrease the risk of a flare, so your doctor may recommend you take an anti-androgen either before or along with an LHRH agonist.

Protecting against effects of a flare is particularly important if you are experiencing pain or other symptoms due to cancer because an increase in testosterone can make those symptoms worse.

An exception to this is the LHRH antagonist degarelix, which doesn't cause a flare in testosterone.

Anti-androgens

These medications don't decrease hormone levels. Instead, anti-androgens block testosterone from reaching cancer cells.

Drugs typically used in this type of hormone therapy include:

  • Bicalutamide (Casodex)
  • Flutamide
  • Nilutamide (Nilandron)

Anti-androgens are given as oral medications. They are usually prescribed along with an LHRH agonist or before taking an LHRH agonist to decrease risks associated with the hormone flare that can be caused by an LHRH agonist.

Surgery to remove the testicles (orchiectomy)

To remove your testicle, your surgeon makes an incision in your groin and extracts the entire testicle through the opening. The procedure is repeated for your other testicle. Prosthetic testicles can be inserted if you choose. You'll receive anesthetics to numb the area during surgery.

All surgical procedures carry a risk of pain, bleeding and infection. Orchiectomy is usually performed as an outpatient procedure and doesn't require hospitalization. Typically, no additional hormone therapy is required following orchiectomy.

Other medications

When prostate cancer persists or recurs despite hormone therapy, other medications can be used to block testosterone in the body. Each medication targets testosterone in the body in a different way. These other medications include:

  • Abiraterone (Zytiga)
  • Corticosteroids, such as prednisone
  • Enzalutamide (Xtandi)
  • Ketoconazole

These other medications are generally reserved for men with advanced prostate cancer that no longer responds to other hormone therapy treatments.

Apr. 26, 2013