NEW YORK (Reuters Health) - A large observational study finds no evidence that use of 5-alpha-reductase inhibitors for benign prostatic hyperplasia (BPH) or alopecia raise the risk of erectile dysfunction.
BPH and alopecia are common conditions in men and the 5-alpha-reductase inhibitors (5ARIs) finasteride and dutasteride are the primary drugs to treat these conditions.
"Our findings should be reassuring that the risk of erectile dysfunction is not higher for men who are prescribed finasteride or dutasteride for BPH or finasteride 1 mg for alopecia. Clinicians should be aware that the longer a man has BPH, the higher his risk for developing erectile dysfunction," Katrina Wilcox Hagberg of the Boston Collaborative Drug Surveillance Program at Boston University School of Public Health, told Reuters Health by email.
Writing online September 22 in The BMJ, Hagberg and colleagues note that while BPH itself is an independent risk factor for ED, some prior evidence suggests that 5ARIs may independently raise the risk of ED. And there is insufficient data on sexual side effects with use of finasteride for alopecia.
To investigate further, the investigators did two cohort studies with nested case-control analyses using the U.K. Clinical Practice Research Datalink.
In the cohort of men with BPH (n=71,849), the risk of ED was not increased with use of 5ARIs only (incidence rate ratio, 0.92; odds ratio 0.94) or 5ARIs plus an alpha blocker (IRR, 1.09; OR, 0.92) compared with alpha-blockers only, "and remained null regardless of number of prescriptions or timing of use," the researchers report in their paper.
"Our study was designed to control for the underlying reason to use 5ARIs (BPH) by comparing two different BPH treatments (5ARIs vs. alpha blockers) and found that the risk of erectile dysfunction was not elevated. We also evaluated the risk of erectile dysfunction associated with longer duration of BPH, which was not considered in clinical trials," Hagberg told Reuters Health.
The risk of ED increased with longer duration of BPH, regardless of exposure, the researchers found.
Similarly, in the cohort of men with alopecia (n=12,346), the risk of ED was not increased for users of finasteride compared with unexposed men with alopecia (IRR, 1.03; OR, 0.95).
These findings suggest that 5ARI therapy does not increase the risk of incident ED, regardless of indication for use, the authors conclude.
Strengths of the analysis include use of a large, validated, longitudinal primary care database known for "high accuracy of diagnoses and completeness of drug prescribing data," the authors say.
"We found known risk factors to be independently associated with risk for erectile dysfunction (eg, increased body mass index, hypertension, hyperlipidemia, diabetes), providing confidence in the quality of the data and its ability to detect associations between benign prostatic hyperplasia treatments and risk of erectile dysfunction," they add.
The average length of follow-up lasted more than four years and the researchers controlled for a range of potential confounders, including non-erectile dysfunction sexual dysfunction, hypertension, diabetes, body mass index, smoking status, depression, and duration of benign prostatic hyperplasia.
A limitation is that drug information in the database covers written, not dispensed prescriptions; "therefore we cannot be sure that patients used all prescribed drugs. However, the relative risks did not change among those with repeat (>=2) prescriptions, suggesting that this did not affect the results," the authors say.
This study was funded by the US National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Diseases. The authors disclosed no current financial conflicts.
Reuters Health Information © 2016
Cite this article: BPH Drugs Don't Independently Raise the Risk of ED: Study - Medscape - Sep 28, 2016.