Degarelix for injection, a gonadotropin-releasing hormone receptor inhibitor, has been approved for treating advanced prostate cancer. Subcutaneous injection forms a depot that continuously and slowly releases degarelix into the circulation, decreasing the release of gonadotropin and consequently the level of testosterone. Degarelix suppresses the activity of testosterone, which slows the growth and progression of prostate cancer.

Unlike another gonadotropin-releasing hormone receptor inhibitor used to treat prostate cancer, leuprolide (Eligard), which initially increases the testosterone level and takes two to four weeks to diminish to a therapeutic level, degarelix begins to decrease the testosterone level immediately. Within a month of initiating therapy, the testosterone level is comparable to that found in patients who have had the testicles surgically removed. The effects of the loss of testosterone include hot flashes, weight gain, diminished sex drive, and erectile dysfunction. Common adverse effects of degarelix include injection site reaction (mostly transient with mild-to-moderate pain, redness, and swelling), fatigue, and elevation of the levels of some liver enzymes.

Nurses should reconstitute degarelix according to the instructions in the product labeling and administer it into the abdomen as indicated. The loading dose includes two injections, and maintenance therapy requires one injection every 28 days.

Ferring Pharmaceuticals Inc. Degarelix for injection for subcutaneous administration. 2008. http://www.fda.gov/cder/foi/label/2008/022201lbl.pdf; FDA approves drug for patients with advanced prostate cancer [press release]. FDA News 2008 29 Dec. http://www.fda.gov/bbs/topics/NEWS/2008/NEW01935.html.