Sexual, physical, and overall adverse effects in patients treated with 5α-reductase inhibitors: a systematic review and meta-analysis

Postfinasteride syndrome (PFS) is a term coined to characterize a constellation of reported undesirable sexual, physical, and neuropsychiatric side effects. In the present study, we conducted the meta-analysis to demonstrate whether the use of 5α-reductase inhibitors (5ARIs) increases the risk of PFS-like adverse effects. A search of studies published until May 10, 2020, was performed using PubMed, EMBASE, and the Cochrane Library. We included randomized controlled trials with at least one comparison between male patients receiving 5ARIs versus placebo for the treatment of benign prostatic hyperplasia (BPH) or androgenetic alopecia (AGA), and identified 34 studies from 28 articles that met our eligibility criteria. In the random-effects model, the overall use of 5ARIs exhibited a 1.87-fold risk of PFS-like adverse effects during the trial (95% confidence interval [CI]: 1.64-2.14). Regarding specific types of adverse effects, the use of 5ARIs had a 1.89-fold risk of sexual adverse effects (95% CI: 1.74-2.05) and was associated with an increased risk of physical adverse effects (relative risk [RR]: 1.31, 95% CI: 0.80-2.15), albeit without statistical significance. This meta-analysis helped to better define the adverse effects caused by 5ARIs. We concluded that the overall use of 5ARIs significantly increased the risk of PFS-like adverse effects in men with AGA or BPH during treatment. Enhanced awareness of and education on the PFS-like adverse effects are necessary for clinicians.