Propecia Use May Cause Erectile Dysfunction. A new study by researchers at Northwestern University has found that men who take the hair-loss medication Propecia may suffer from erectile dysfunction for months or even years after they stop taking the drug.
“We expect that our finding of an association between debilitating sexual dysfunction and exposure to finasteride or dutasteride will be of particular interest to prescribers and patients” considering treatment options, the authors wrote.
The new study was published in March 2017 in the open-access peer-reviewed journal PeerJ.
The researchers found that of 15,634 men who took finasteride—the main ingredient in Propecia—and who had no prior sexual dysfunction, 699 (4.5%) experienced new erectile dysfunction and 210 (24.3%) experienced new low libido. Of 11,909 men who used finasteride and had no previous sexual dysfunction, 167 (1.4%) developed persistent erectile dysfunction that lasted for at least 90 days (with a median of 1,348 days) after they stopped taking the drug.
The study also found that young men who took finasteride or dutasteride (Avodart, a prostate medication) for longer than 205 days had a 4.9-fold higher risk of persistent erectile dysfunction than men who took the drugs for shorter periods.
The researchers write, “Men who had taken [Propecia] were more likely than non-exposed men to have had a recording of erectile dysfunction in their medical records, with on average one case for every 17 men prescribed the drugs.” These men were more likely to have recordings of low libido and to have been prescribed an erectile dysfunction drug like Viagra.
Parker Waichman notes that in addition to sexual side effects, some men who have taken Propecia have experienced suicidal thoughts, and some have committed suicide.
The U.S. Food and Drug Administration (FDA) approved Proscar (the 5 mg dose of finasteride) in 1992 for the treatment of benign prostate enlargement. In 1997, Propecia (the 1mg dose) was approved for the treatment of male-pattern baldness. After the FDA approved Propecia, the medication came with a warning of possible side effects including decreased libido and erectile dysfunction. Propecia and Proscar have been prescribed to more than one million men in the United States.
Propecia use has been linked to serious sexual side effects including:
- erectile dysfunction (ED)
- loss of sex drive
- low libido
- inability to achieve orgasm
Some men have experienced suicidal thoughts, and some men have reportedly committed suicide.
In 2012, after reviewing post-marketing reports for Propecia, the FDA directed Merck to update warning labels for finasteride medications to include information about sexual side effects that could continue after treatment ends. The revision to the Propecia label to includes libido disorders, ejaculation disorders, and orgasm disorders that continued after discontinuation of the drug. The Proscar label revision included a warning that decreased libido could continue after the man stopped taking the drug.
The labels reflect the differences in the population of men using Propecia and Proscar, the FDA explained. Sexual dysfunction that continued after patients stopped using Propecia occurred in a younger population of men compared to cases reported with Proscar. Older men who reported sexual adverse events with Proscar, in general, also had concurrent medical conditions and they also took medications that may affect sexual function.
The FDA communication to prescribers notes that the agency has not established a cause and effect relationship between finasteride—Propecia and Proscar—and the sexual adverse events that continued after stopping drug use.
Propecia users in the U.S. and Canada have filed lawsuits against Merck & Co., the maker of Propecia, alleging that the medication caused serious side effects, including sexual dysfunction and mental and emotional problems. Plaintiffs allege that side effects such as sexual dysfunction, insomnia and emotional symptoms persisted for years, even after the men stopped taking the hair-loss treatment. The plaintiffs accuse Merck of failing to warn patients that the sexual side effects may be permanent, continuing even after the man stopped taking the drug.
The study also found that the length of time that the men in the study took finasteride was a more accurate predictor of persistent erectile dysfunction than other know risk factor such as age, hypertension, diabetes mellitus, smoking, ethanol abuse, obesity and depression.