Placebo Responses Among Men With Erectile Dysfunction Enrolled in Phosphodiesterase 5 Inhibitor Trials

Abstract

IMPORTANCE Placebo responses in the treatment of erectile dysfunction (ED) are poorly described in the literature to date. OBJECTIVE To quantify the association of placebo with ED outcomes among men enrolled in placebo-controlled, phosphodiesterase 5 inhibitor (PDE5I) trials. DATA SOURCES For this systematic review and meta-analysis, a database search was conducted to identify double-blind, placebo-controlled studies using PDE5Is for the treatment of ED published

The Use of Vasoactive Drugs in the Treatment of Male Erectile Dysfunction: Current Concepts

“…Since, under conditions of sexual stimulation, the pro-erectile effects of PDE5 inhibitors are dependent upon the unimpaired function of cavernous nerves (releasing the gaseous neurotransmitter NO) innervating the vascular and non-vascular penile smooth musculature, the treatment effect is mediocre to poor in patients who had undergone non-nerve sparing pelvic surgeries [15]. This is well in accordance with the results from a recent meta-analysis indicating that the placebo effect shows a tendency to be much more pronounced among subjects with ED associated with post-traumatic stress disorder (for example, following pelvic/prostatectomy surgery) with almost no significant differences between the treatment effects exerted by placebo and PDE5 inhibitors [16]. To date, due to the fact that a vast majority of patients require a permanent solution to overcome their ED and also in an effort to abandon the stepwise approach of adjusting the treatment regimen, an increasing number of men, following comprehensive information about the various treatment options (PDE5 inhibitors, intracavernosal injections, intraurethral/topical alprostadil) are given the opportunity of choosing the treatment that suits them best [17].…”

Efficacy and Safety of Avanafil in Chinese Subjects With Erectile Dysfunction: A Multi-Center, Randomized, Double-Blinded, Placebo-Controlled Phase III Clinical Trial

“…Commonly, psychogenic factors are important in the pathogenesis of ED in young subjects, [22,23] and the placebo was associated with an improvement in psychogenic ED. [24] The changes in mean IIEF-EF domain scores in the avanafil groups were significantly improved in PDE5i naive cases who received the avanafil 100 mg (P = .010) and subjects who previously received PDE5i and were distributed to the avanafil 200 mg (P = .048) group. In the avanafil 200 mg group, improvements in erectile function were higher in previously PDE5i medicated cases than for PDE5i naïve cases (10.3 § 7.8 vs 7.3 § 6.3, P = .140), which may indicate that avanafil may be used as a PDE5i salvage therapy at a dose of 200 mg.…”

Assessment of Combination Therapies vs Monotherapy for Erectile Dysfunction

“…4 , 5 , 6 However, more than half of the patients have reported dissatisfaction, presented low adherence rates, or even abandoned the first-line ED therapeutic options because of lack of efficacy, inconvenient administration, adverse events (AEs), or contraindications. 7 , 8 , 9 Before considering penile prosthesis implant, individuals may use a combination of 2 or more first-line ED treatments or other modalities in addition to first-line ED treatments, which seems, in this context, to be associated with beneficial outcomes. 10 Moreover, in some individuals with curable causes of ED, such as hypogonadism, the coadministration of ED treatments and population-targeted therapies, such as testosterone, may prove successful.…”