Study Suggests Propecia Side Effects Are Long-Lasting

Washington, DCA new study suggests Propecia side effects could be more permanent than patients and physicians previously thought. Although studies have shown a risk of Propecia side effects in men, including sexual dysfunction, the drug's warning label stated that the side effects were temporary and would resolve once the Propecia and Proscar were discontinued. Now, however, research indicates that patients could be at risk of Propecia long-term side effects.

The study, published in the Journal of Sexual Medicine (7/12/12), involved following up with men who had persistent sexual side effects between nine and 16 months after discontinuing the medication. The subjects were all healthy men under the age of 40 who had no sexual dysfunction or medical conditions before taking finasteride (the generic version of Propecia). Researchers found that at the time of follow-up, persistent sexual side effects were still present in 96 percent of the subjects.

"In most men who developed persistent sexual side effects [those that lasted for three months or more] despite the discontinuation of finasteride, the sexual dysfunction continued for many months or years," researchers concluded.

The study size was small—54 men in total—and all men had already experienced sexual side effects linked to Propecia. Some of the men reportedly took Propecia for only a few weeks, but others took it for years. Among the side effects they reported were erectile dysfunction, decreased sexual drive and painful genitals. Some men also reported depression and difficulty with cognition.

Propecia is used to treat male pattern baldness in men, while a more concentrated version of finasteride, known as Proscar, is used to treat enlarged prostates. Most side effects linked to the two medications are thought to resolve once medication is discontinued, but recent studies suggest that the adverse effects could continue for years after final exposure to the drugs.

Overall, the percentage of men who experience long-term Propecia side effects is likely small, but given how frequently Propecia is prescribed, there could be many men at risk of suffering persistent sexual side effects.

In April 2012, the US Food and Drug Administration (FDA) announced changes to the warning label of both Propecia and Proscar. The label was updated to expand the list of sexual side effects linked to the drugs because some of those side effects continued after the drug was stopped.