The Food and Drug Administration announced June 9, 2011 that the "Warnings and Precautions" section of labeling for the 5-alpha reductase inhibitor (5-ARI) class of drugs has been revised to include new safety information about the increased risk for high-grade prostate cancer. Drugs in the 5-ARI class are finasteride and dutasteride, which are marketed under the names Proscar, Propecia, Avodart, and Jalyn.
The new safety information is based on the FDA's review of two large, randomized controlled trials: the Prostate Cancer Prevention Trial (PCTC) and the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial. The PCTC trial evaluated daily use of finasteride versus placebo for 7 years and the REDUCE trial evaluated the use of dutasteride versus placebo for 4 years.
In both trials there was an overall reduction in prostate cancer diagnosis, however, there was also an increased incidence of high-grade prostate cancer. While the risk appears to be low, the FDA felt healthcare professionals should be aware that the risk exists so that they can accurately weigh the benefits against potential risks when determining treatment options.
Proscar, Avodart, and Jalyn are most commonly used to treat symptoms of an enlarged prostate. Propecia is approved to treat male pattern baldness. Approximately 5 million male patients received a prescription for a 5-ARI between the years of 2002 and 2009.