Canadian Officials Site Male Breast Cancer as Risk of Propecia

The side effects of Propecia, a popular hair loss medication, may increase the risk that men experience erectile dysfunction, decreased libido and other sexual problems, which have been permanent in some cases.  Research has suggested that only about half of men who experienced sexual side effects of Propecia have the problems resolve after they stop the medication. Other studies have found that the mean duration of Propecia erectile dysfunction was 40 months, with 20% of subjects reporting durations over 6 years. In addition to this, there have also been shown to be links between Propecia and male breast cancer. Canadian health officials have issued a new warning

about the risk of male breast cancer from side effects of Propecia and Proscar, which are used to treat male pattern hair loss and enlarged prostates. 

The Canadian warning comes after the FDA issued a prostate cancer warning for Propecia and Proscar in June. 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 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. Side effects of Propecia have been linked to an increased risk of irreversible sexual problems that may persist even after use of the medication is stopped. Although it appears that Merck knew or should have known about this risk of Propecia problems, they failed to adequately warn consumers or the medical community, placing their desire for profits before the safety of men using the medication.