5-ARI use does not raise erectile dysfunction risk

Boston-The risk of erectile dysfunction (ED) is not increased with the use of a 5-alpha-reductase inhibitor (5-ARI) compared with an alpha-blocker for the treatment of BPH.

In a nested case-control study involving more than 70,000 men with BPH, the incidence rate ratio (IRR) of ED was 0.92 with the use of a 5-ARI alone and 1.09 with the use of a 5-ARI plus an alpha-blocker compared with an alpha-blocker only, reported J. Curtis Nickel, MD, at the AUA annual meeting in Boston.

“If you don’t get ED on 5-ARI right away, any ED that you see over the course of time is likely the natural aging process,” said Dr. Nickel, professor of urology at Queen’s University, Kingston, Ontario. “I think this sets to rest one of the major complications of 5-ARIs that we’ve always been concerned about, and we can reassure physicians prescribing and patients receiving 5-ARIs that there’s no increased risk than if they received alpha-blockers alone.”

Early studies of 5-ARIs suggested an increased early risk of ED.

“That increased risk of ED appeared to occur in the first 3 months or so, but then after that there did not appear to be any further increase over placebo,” he said. “However, we have this hanging over our heads that 5-ARIs cause ED and we have the specter of this so-called post-finasteride syndrome.”

In the study presented at the AUA annual meeting, 71,849 men 40 years of age and older with a diagnosis of prostatism or BPH who received at least one prescription for a 5-ARI, an alpha-blocker, or both over a 20-year period (1992 to 2011) were identified from United Kingdom’s Clinical Practice Research Datalink. The men had no history of ED in their charts for at least 3 years prior to the cohort entry date.

Included were 5,814 men with newly diagnosed ED over the 20 years. ED cases were men who had a diagnosis of ED or impotence, were prescribed a phosphodiesterase-type-5 inhibitor, or had a procedure for the treatment of ED (ie, penile prosthesis, penile injection, or other operation for the treatment of ED) recorded during follow-up.

There were 4,665 cases of ED with use of an alpha-blocker only, with 231,724 person-years of follow-up; 727 cases with use of a 5-ARI only over 47,369 person-years of follow-up; and 422 cases of ED with use of both a 5-ARI and an alpha-blocker over 22,008 person-years. The incidence rate of ED was lowest among users of 5-ARIs only, at 15.3 per 1,000 person-years. In the ED cohort study, the incidence rate of ED was similar between those who used both a 5-ARI and an alpha-blocker (19.2 per 1,000 person-years) and an alpha-blocker only (20.1 per 1,000 person-years).

There was no elevation in risk of ED with the use of a 5-ARI only (IRR 0.92, 95% CI: 0.85-0.99) or use of a 5-ARI with an alpha-blocker (IRR 1.09, 95% CI: 0.99-1.21) compared with an alpha-blocker only.

Next: Results null regardless of timing of use

Results null regardless of timing of use

In the cohort study, the odds ratio for ED was 0.94 (95% CI: 0.85-1.03) with use of a 5-ARI only and 0.92 (95% CI: 0.80-1.06) for use of both a 5-ARI and an alpha-blocker compared with an alpha-blocker only. A nested case-control analysis in which each man with ED was matched with at least four men without ED revealed that the results remained null regardless of the number of prescriptions or the timing of use.

In an analysis stratified by duration of BPH, the risk of ED increased with longer duration of BPH, regardless of 5-ARI exposure. For instance, with BPH duration of 6 months to 1 year, the odds of ED were 1.15 with an alpha-blocker only, 0.96 with a 5-ARI only, and 0.96 when using both. With BPH duration of 5 years or longer, these odds increased to 2.80 with an alpha-blocker only, 1.54 with a 5-ARI only, and 2.55 with use of both.

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The real-world data examined are an advantage over previous studies exploring the relationship between 5-ARI use and ED, said Dr. Nickel.

“This is a real-life clinical situation of ED presenting to physicians so it’s clinically meaningful, whereas in the other studies it’s not… patients didn’t care and didn’t want to be treated,” he said.

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