Most prostate cancers need the male hormone testosterone to grow. Testosterone is an androgen (type of hormone) made by the testes and adrenal glands. Degarelix is an anti-androgen medication. Anti-androgen therapies work by blocking an enzyme needed for the making of testosterone. By blocking the making of testosterone, the cancer cells may either grow more slowly or stop growing completely.

Degarelix is a man-made form of a protein that blocks the production of gonadotropin-releasing hormone (GnRH) by the pituitary gland. GnRH stimulates (revs up) the testes to produce testosterone. By blocking GnRH, degarelix lowers your body's level of testosterone.

How to Take Degarelix

Degarelix is given as a deep subcutaneous injection (SQ, under the skin). The injection is designed to slowly release the medication over the next 4 weeks.

Possible Side Effects of Degarelix

There are a number of things you can do to manage the side effects of degarelix. Talk to your care team about these recommendations. They can help you decide what will work best for you. These are some of the most common or important side effects:

Injection Site Reactions

The injection site may become red, swollen, tender or you may be able to feel a lump. These side effects are temporary. The injection is given in your abdomen (belly). Make sure the area will not have any pressure on it from belts, waistbands, or other types of clothing.

Hot Flashes

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 fluoxetine), and gabapentin. Talk to your healthcare team about these prescription products to see if they are right for you.

Non-medical recommendations are to:

Keep well-hydrated with eight glasses of water daily.
Drink ice water or apply an ice pack at the beginning 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 meditation or relaxation exercises to manage stress, which can be a trigger.
Avoid triggers such as warm rooms, spicy foods, drinks with caffeine, and alcohol.

Weakening of the Bones (Osteoporosis)

Men who take hormone therapy for long periods of time are at risk for bone thinning (osteoporosis). You may be told 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 also help protect your bone health. You may have a bone density scan (DEXA scan) to check your bone health. If your healthcare provider thinks that you are at high risk of developing osteoporosis, they may suggest other treatment with a type of medication called a bisphosphonate to help strengthen the bones.

Important but Less Common Side Effects

Hypersensitivity: Some patients may have a reaction to the medication itself. If you are having trouble breathing, have a new rash, or develop swelling in any part of your body, call your care team right away.
Weight Gain: Some men have weight gain. Exercise and dietary changes may be helpful.
Liver Toxicity: In clinical trials, some patients had increases in blood tests called liver function tests. These changes got better when the medication was stopped.
Cardiac Toxicity: This medication can affect the electrical conduction in your heart muscle (called QT prolongation). Make sure your provider is aware of any history of heart problems or heart medications you may be taking.
Breast Tenderness or Increase in Breast Tissue: An increase in breast tissue (gynecomastia) or breast tenderness may happen. Your healthcare team can suggest medications to relieve tenderness. In rare cases, radiation can be given to relieve severe tenderness.

Sexual and Reproductive Changes

This drug can affect your reproductive system, resulting in sperm production becoming irregular or stopping permanently. In addition, you may experience erectile dysfunction or a decreased desire for sex during treatment. Talk to your urologist about options for treating erectile dysfunction.

Exposure of an unborn child to this medication could cause birth defects, so you should not father a child while on this medication. Effective birth control is necessary during treatment, even if you believe you are not producing sperm.

Degarelix (Firmagon®)