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Trade/other name(s): Firmagon

Why would this drug be used?

Degarelix is used to treat advanced prostate cancer. It is also being studied for use in other conditions.

How does this drug work?

Degarelix belongs to the general class of drugs known as hormones or hormone antagonists. It blocks gonadotropin-releasing hormone (GnRH), also known as luteinizing hormone-releasing hormone (LHRH). This lowers the level of the male hormone testosterone in the blood. Since prostate cancer usually depends on testosterone to help it grow and spread, this helps stop it from growing.

Before taking this medicine

Tell your doctor…

  • If you are allergic to anything, including medicines, dyes, additives, or foods.
  • If you have any type of heart disease, congestive heart failure, heart rhythm problems, long QT syndrome (a rare condition that prolongs the heart’s electrical pathway), or problems with electrolyte (body salt) balance, such as sodium, potassium, calcium, or magnesium. These conditions may require that you be observed more closely during treatment.
  • If you have liver or kidney problems. This drug is removed from the body by the liver and kidneys, so your doctor might need to watch you more closely.
  • If you have osteoporosis (weakened or thinned bones). Degarelix may make this problem worse.
  • If you have any other medical conditions, such as diabetes, high blood pressure, gout, or infections. Your doctor might need to watch you more closely during treatment.
  • If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. This drug may cause birth defects if taken at the time of conception or during pregnancy. This drug should not be used by women who are or could become pregnant.
  • If you are breast-feeding. It is not known whether this drug passes into breast milk. If it does, it could harm the baby.
  • If you think you might want to have children in the future. It is not known whether or not this drug can affect fertility. Talk with your doctor about the possible risk with this drug and the options that may preserve your ability to have children.
  • About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

If this drug is used with other medicines that affect heart rhythm, such as amiodorone (Cordarone, Pacerone), disopyramide (Norpace), dofetilide (Tikosyn), flecainide (Rhythmol), ibutilide (Corvert), procainamide (Procan, Pronestyl), propafenone (Tambocor), quinidine (Quinidex, Cardioquin), or sotalol (Betapace), it may increase the risk of dangerous heart rhythms.

Check with your doctor, nurse, or pharmacist about other medicines, vitamins, herbs, and supplements, and whether alcohol can cause problems with this medicine.

Interactions with foods

No serious interactions with food are known at this time. Check with your doctor, nurse, or pharmacist about whether foods may be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

Degarelix is given as 2 injections under the skin for the first dose, then 1 injection once a month, usually in the abdomen (belly). The dose is the same for all patients being treated for prostate cancer. Your doctor will test your testosterone blood levels before treatment, then at 4 weeks, and then every 8 weeks after that to see how well the treatment is working.


Degarelix can increase the time it takes for the heartbeat impulse to pass through the heart. Call the doctor or nurse right away if your heart rate changes or becomes irregular, if you feel lightheaded or pass out (faint), or have a seizure.

Rarely, people have allergic reactions after getting this drug, with symptoms such as hives (raised, itchy spots); trouble breathing or swallowing; swelling of the lips, mouth, or throat; and/or dizziness. Tell your doctor or nurse right away if you have any of these problems.

The effects of degarelix in women and children have not yet been studied.

Possible side effects

You will probably not have most of the following side effects, but if you have any talk to your doctor or nurse. They can help you understand the side effects and cope with them.


  • Hot flashes
  • Trouble sleeping
  • Pain, redness, and swelling at the injection site
  • Enlarged breasts
  • Breast pain, nipple tenderness
  • Back pain
  • Constipation
  • Headache
  • Fatigue
  • Increased urination
  • Low sex drive
  • Trouble getting erections

Less common

  • Swelling of hands and feet
  • Dizziness
  • Upper respiratory tract infection
  • Nausea
  • Diarrhea
  • Pain when urinating
  • Trouble urinating
  • Urinary tract infection
  • Swollen testicles
  • Weight gain
  • Osteoporosis (thin or weakened bones) with longer treatment
  • Abnormal blood test results which suggest that the drug is affecting the liver (your doctor will discuss the importance of this finding, if any.)


  • Allergic reaction*
  • Changes in the way your heart conducts electrical impulses*

*See the “Precautions” section for more detailed information.

There are some other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA approval

Yes – first approved in 2008

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.

Last Medical Review: 05/23/2013
Last Revised: 05/23/2013