The FDA is evaluating whether gonadotropin-releasing hormone, or GnRH, agonists increase the risk of diabetes and certain cardiovascular diseases in men who receive these medications to treat prostate cancer.
The drugs are marketed by various pharmaceutical manufacturers as generic medications and under the brand names Eligard, Lupron, Synarel, Trelstar, Vantas, Viadur and Zoladex. They are used in androgen deprivation therapy, or ADT, which has been shown to slow the growth of prostate cancer and even shrink prostate tumors by suppressing testosterone.
The FDA said in a May 3 news release(www.fda.gov) that its review is ongoing, and the agency has not reached any conclusions about whether the products increase the risk of developing diabetes or cardiovascular disease. However, according to a May 3 safety communication from the agency(www.fda.gov), data from six studies that compared outcomes in patients undergoing ADT with those in patients not undergoing the treatment indicate a small increased risk for these conditions.
The FDA offered the following advice for physicians and patients:
- physicians should carefully weigh the benefits and risks of prescribing GnRH agonists when determining treatment;
- patients receiving GnRH agonists should be monitored for development of diabetes and cardiovascular disease;
- physicians should manage patients' cardiovascular risk factors, such as smoking and increases in blood pressure, cholesterol, blood sugar, and weight, according to current clinical practice; and
- patients should not stop their treatment with GnRH agonists unless told to do so by their physicians.
The agency's recommendations are consistent with a science advisory(circ.ahajournals.org) issued by the American Heart Association, the American Cancer Society and the American Urological Association in the February issue of Circulation.
GnRH agonists also are used in children to treat central precocious puberty, as well as in women for the management of endometriosis, preoperative improvement of anemia caused by uterine fibroids and palliative treatment of advanced breast cancer. However, the FDA said there are no known comparable epidemiologic studies evaluating the risk of diabetes and cardiovascular disease in children or women.