Impact of Alpha Blockers, 5-Alpha Reductase Inhibitors, and Combination Therapy on Sexual Function

The 2014 document reviews the sexual side effects of medications for benign prostatic hyperplasia (BPH), including alpha blockers (ABs), 5-alpha reductase inhibitors (5-ARIs), and their combination therapy. It notes that ABs can cause ejaculatory dysfunction (EjD), with the incidence varying by the specificity of the AB, and that the effects on erectile function and libido are less clear. The 5-ARIs, which reduce prostate size by inhibiting testosterone conversion, may also affect sexual function by altering neurosteroid levels. Large placebo-controlled trials have reported adverse sexual effects such as diminished libido, erectile dysfunction (ED), and EjD, particularly within the first year of 5-ARI therapy. These effects are statistically significant and may persist after stopping the medication. The document also discusses the "nocebo phenomenon," where awareness of potential side effects increases reporting of ED, decreased libido, and EjD. Combination therapy has the highest rate of sexual adverse events, with 5-ARI being the main contributor. Despite the significant effects on sexual function, the small number of men affected is seen as encouraging, but more research is needed to understand why some men are more susceptible to these effects.