Sexual Problems Tied to Prolonged Use of Prostate Drugs, Study Says

For men forced to manage an oversized prostate, some words of caution. Treating the condition for too long with commonly-prescribed medication may control that problem – while creating another that can prevent them from having sex.

A new study released today finds that men who take either of two prostate-reduction drugs for a prolonged period have a greatly higher chance of experiencing a prolonged bout of erectile dysfunction.

In addition, according to researchers, "some men may not be able to have normal erections for months or years" – even after going off the drug.

Those are the primary conclusions from a Northwestern University study assessing the impact of the finasteride or dutasteride – known by the brand names Propecia and Proscar, and Avodart and Jalyn, respectively – on men's ability to function sexually. What's more, relatively young males who stayed on these drugs for more than six months, researchers report, produced a five-times greater chance of them being unable to perform. 

Of the nearly 12,000 men involved in the analysis, 1.4% "developed persistent erectile dysfunction that continued for a median of 1,348 days after stopping the drugs," according to the university. And those "under 42 years old who had more than 205 days of finasteride or dutasteride exposure had 4.9-fold higher risk of persistent erectile dysfunction than men with shorter exposure."

According to the study's lead author, men who take these drugs "can get persistent erectile dysfunction, in which they will not be able to have normal erections for months or years after stopping finasteride or dutasteride," says Dr. Steven Belknap, a research assistant professor of dermatology at Northwestern University Feinberg School of Medicine. 

That said, it's important to understand the two uses of finasteride, the ingredient in Proscar and Propecia, which treat different conditions – and the varying impact of each.

"The only difference between the two is dose and use,” states Dr. Josh Bloom, our Director of Chemical and Pharmaceutical Sciences. "Proscar, which is used to treat an oversized prostate, contains 5 mg of finasteride. Meanwhile Propecia, prescribed for hair loss, contains 1 mg. So those men who take Proscar are more likely to suffer from erectile dysfunction than those who take Propecia to prevent hair loss."

The study, "Persistent erectile dysfunction in men exposed to the 5α-reductase inhibitors, finasteride, or dutasteride," was published in the journal PeerJ.