Sexual effects data lacking on 5-ARI for hair loss

In men who take the 5-alpha-reductase inhibitor finasteride (Propecia) for hair loss, published data on its sexual side effects are insufficient to create a safety profile of the drug, according to a recent study.

The study, which was published in JAMA Dermatology (April 1, 2015), raises several questions but does not alter current thinking on the subject, according to one men’s health expert. Urologists are more familiar with the use of finasteride, 5 mg, as a treatment for BPH, for which it was originally marketed under the name brand Proscar. The agent’s 1-mg dose is indicated for androgenic alopecia (AGA).

In the retrospective review, researchers from Northwestern University Feinberg School of Medicine, Chicago examined 34 trials of finasteride, for AGA, concluding: "Available toxicity information from clinical trials of finasteride in men with AGA is very limited, is of poor quality, and seems to be systematically biased."

The data in the trials, as published, are insufficient to create a safety profile of finasteride as a treatment for AGA, concluded the authors, led by Steven M. Belknap, MD.

Not one of the 34 trials under analysis had adequate safety reporting, the authors said. A total of 19 were deemed partially adequate and 12 were said to be inadequate. Three of the 34 studies reported no adverse events. The studies encompassed 9,751 subjects with a mean age of 35.5 years. A total of 29 trials evaluated the 1-mg dose of finasteride, two studies evaluated doses of both 1 and 5 mg, and three evaluated a dose of 5 mg. Safety evaluations were drawn from a year or less of data in 26 (76%) of the trials.

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Dr. Belknap, in a press release accompanying the study's publication, said the status of today's literature leaves a number of questions unanswered, such as the safety of long-term treatment with finasteride in men with AGA, the incidence of sexual dysfunction in these men, and whether function returns on cessation of treatment.

“People who take or prescribe the drug assume it’s safe, but there is insufficient information to make that judgment,” Dr. Belknap said.

NEXT: Questions regarding how sexual dysfunction was reported

Urology Times Editorial Council member Steven A. Kaplan, MD, of Weill Cornell Medical College, New York, had several questions regarding how sexual dysfunction was reported for the studies under review.

“We know that some men can have these effects. Was this asked before taking finasteride? I suspect that only self-reported issues were logged. Moreover, I suspect that as over time more was known about the potential effects of finasteride on sexual function, it was queried,” said Dr. Kaplan, who was not involved with the study.

"Is this something doctors should take into consideration when advising men who want something for their baldness? The bottom line is that in today's world, as part of informed consent, the possibility [of sexual dysfunction] needs to be raised. This abstract does not change the current state of knowledge," he said.