Propecia, Avodart Prostate Cancer Warning Issued by FDA

Side effects of Propecia, Avodart and similar drugs could raise the risk of prostate cancer, U.S. health officials warned this week. 

The FDA issued a drug safety alert for Propecia, Avodart, Proscar and Jalyn on Thursday, saying that the hair loss and enlarged prostate treatment drugs could increase the risk of prostate cancer’s more serious forms. The FDA is adding new warning labels to the drugs to alert consumers of the risk.

All of the drugs belong to a class of medications known as 5-alpha-reductase inhibitors. They reduce hair loss and can shrink an enlarged prostate by blocking a hormone known as dihydrotestosterone (DHT). The drugs have also been linked recently to erectile dysfunction and other sexual side effects in men.

The FDA warning comes after the agency reviewed two large, randomized controlled trials known as the Prostate Cancer Prevention Trial (PCPT) and the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial. The trials found that the drugs reduced the overall risk of low risk prostate cancer. However, they increased the risk of more dangerous high-grade prostate cancer. The risk and severity of prostate cancer is measured using what is called the Gleason Scale (GS). Prostate cancers with a GS score of 6 or less were reduced by the drugs, while GS 8-10 prostate cancer risks were increased.

Propecia (finasteride) was approved in 1992 for the treatment of benign prostatic hyperplasia, and also is approved to treat male pattern baldness. It was originally marketed by Merck as Proscar.

Avodart (dutasteride) is a GlaxoSmithKline drug that was approved by FDA for the treatment of urinary problems in October 2002. Jalyn is a combination of Avodart and Flomax; another drug used to treat enlarged prostates.

In its warning the FDA noted that none of the drugs were approved to treat prostate cancer.

In March, researchers from the U.S. published a study in the Journal of Sexual Medicine that found side effects of Propecia and similar drugs were linked to sexual problems in men. Researchers indicated that 5-alpha-reductase inhibitors can cause loss of libido, depression erectile dysfunction, reduced semen production and growth of male breast tissue. They also agreed that in some cases these side effects appeared to be permanent.