番茄社区

SAN FRANCISCO -- Sexual adverse events occurred significantly more often in younger men who used finasteride (Propecia) to treat hair loss as compared with nonusers, data from a large patient record system showed.

Although the absolute numbers of men affected were small, exposure to low-dose finasteride tripled the likelihood of an impotence diagnosis and conferred almost a five-fold increase in the frequency of prescriptions for sexual-performance drugs and diagnoses of low libido.

Of more than 1,400 men 42 or younger included in the the analysis, 52 had a history of low-dose finasteride therapy. Nonetheless, investigators characterized the association between finasteride and sexual adverse events as "clinically and statistically significant," as reported here at the American Academy of Dermatology meeting.

"There is a high statistically significant risk of all measured outcomes -- impotence, phosphodiesterase 5 (PDE5) inhibitors, and diminished libido in men younger than 42 who were prescribed finasteride at a dose of less than or equal to 1.25 mg/day for androgenic alopecia compared to men who had no exposure to a 5-alpha reductase inhibitor," Tina Kiguradze, of the Feinberg School of Medicine at in Chicago, and colleagues concluded in a poster presentation.

"Detected safety signals indicating risks of impotence and diminished libido for the use of finasteride in the management of androgenic alopecia support the need for increased awareness in both patients and prescribers."

Initially approved in 1992 for treatment of benign prostatic hyperplasia (BPH), finasteride received FDA approval in late 1997 for hair loss in men (androgenic alopecia). The typical dose for treating BPH is 5 mg/day, as compared with 1 mg/day for treatment of hair loss. Adverse events occur infrequently with the 1 mg-dose, and a meta-analysis of clinical trials found an impotence rate of one in 80 men who received finasteride 1 mg/day for androgenic alopecia.

Since the approval of finasteride for male hair loss, sporadic reports have suggested persistent erectile dysfunction occurs in some men treated with the 1 mg/d-dose of the 5-alpha reductase inhibitors. Kiguradze and colleagues undertook a review of medical records to examine the occurrence of sexual adverse events in younger men using finasteride for hair loss and to characterize the type and frequency of the events.

Investigators searched the 2.9 million patients in the Northwestern electronic health records (EHR) system for the time period January 1992 to September 2013. They identified all male patients who were younger than 42, had no history of sexual dysfunction prior to exposure to finasteride, had otherwise good physical and mental health, and had received finasteride at doses no greater than 1.25 mg/d.

The record search identified 157,998 healthy men younger than 42, including more than 1,441 who had a history of low-dose finasteride therapy for treatment of hair loss. In the subgroup of finasteride users, Kiguradze and colleagues identified 17 men with diagnoses of impotence, 26 men who had a history of prescriptions for PDE5 inhibitors (such as sildenafil), and nine men who had diagnoses of low libido.

As compared with men who had no history of use of low-dose finasteride, the users had the following risks, including number needed to harm (NNH):

• Impotence diagnosis: NNH=129, HR 2.93 (P=0.00008)
• PDE5 inhibitor use: NNH=70, HR 4.75 (P<0.000001)
• Low libido diagnosis: NNH=201, HR 4.91 (P=0.00013)

Urologist , said the study did not identify any new issues and should not have an impact on current clinical practice.

"We know that some men can have these effects," Kaplan, of Weill Cornell Medical College in New York City, told 番茄社区 by email. "Was this asked before taking finasteride? I suspect that only self-reported issues were logged. Moreover, I suspect that over time, as more was known about the potential effects of finasteride on sexual function, it was queried."

"The bottom line is that in today's world, and as a part of fully informed consent, the possibility needs to be raised," he added. "This abstract doesn't change the current state of knowledge."

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