Federal health regulators have warned that a class of prostate cancer drugs called Gonadotropin-Releasing Hormone (GnRH) agonists have been associated with a small increase in the risk of diabetes, heart attack and strokes. GnRH agonists are marketed under the brand names Eligard, Lupron, Synarel, Trelstar, Vantas, Viadur, and Zoladex. There are also several generic products available.
The alert, issued yesterday, was based on preliminary and ongoing analysis of several studies by the U.S. Food and Drug Administration (FDA). The agency noted that it has not yet reached any conclusions about whether GnRH agonists cause an increase in the risk of diabetes and heart disease in patients receiving one of these medications to treat prostate cancer.
“While our review of these prostate cancer treatments is ongoing and there are some limitations to the data, FDA believes it is important to tell patients and health care professionals that there may be an increased risk of serious side effects,” said Robert Justice, M.D., director of the Division of Drug Oncology Products in FDA’s Center for Drug Evaluation and Research.
Based on its initial findings, the FDA advises:
• Health care professionals should be aware of these potential risks and carefully weigh the benefits and risks of GnRH agonists when determining a treatment for patients with prostate cancer.
• Patients receiving a GnRH agonist should be monitored for the development of diabetes and cardiovascular disease.
• Cardiovascular risk factors such as smoking and increases in blood pressure, cholesterol, blood sugar and weight should be managed according to current clinical practice.
• Patients should not stop treatment with a GnRH agonist unless instructed to do so by a health care professional.
Prostate cancer is the second most common type of cancer among men in the U.S. This year an estimated 203,415 new cases of prostate cancer will be diagnosed and about 28,372 men will die from the disease, according to the Centers for Disease Control and Prevention.
GnRH agonists are drugs that suppress the production of testosterone, a hormone that is involved in the growth of prostate cancer. This type of treatment is called androgen deprivation therapy, or ADT. Suppressing testosterone has been shown to shrink or slow the growth of prostate cancer.
GnRH agonists are also used to help manage the pain caused by endometriosis, to improve anemia associated with uterine fibroids prior to hysterectomy and in some cases for palliative treatment of advanced breast cancer. In addition, these drugs have also been given to children to treat central precocious puberty. According to the FDA, there are no known comparable studies that have evaluated the risk of diabetes and heart disease in women and children.