Endothelial Dysfunction in Patients With Erectile Dysfunction: A Double-Blind, Randomized-Control Trial Using Tadalafil

To assess whether tadalafil improves endothelial dysfunction(EnD) in a placebo-controlled randomized-control trial.

Erectile dysfunction and EnD were assessed by the International Index of Erectile Function (IIEF-5) and flow-mediated dilation (FMD) of the brachial artery respectively, at baseline and 4 weeks by blinded observer. Patients with FMD of < 15% were randomized in 1:1 ratio to receive either placebo or tadalafil. Both placebo and tadalafil in similar-appearing capsules but coded separately, were dispensed by a blinded co-investigator. Compliance and drug-related events were recorded. The randomization codes were then decoded and appropriate statistical tests applied.

89 patients were randomized and 82 completed the study. Both groups were comparable. Posttreatment, there were significant improvements in IIEF-5 score (pre- vs posttreatment; tadalafil: 11.432 vs 15.937, P < .001 and placebo 11.232 vs 14.935, P < .00) and FMD% pre- vs posttreatment; tadalafil: 11.222 vs 13.827, P < .001 and placebo: 11.617 vs 14.027, P < .001). Intergroup comparison did not show any significant difference in IIEF scores (mean change in tadalafil vs placebo group: 3.719 vs 4.433, P = .223) and FMD% (mean change tadalafil vs placebo group: 2.426 and 2.829, P = .528). The adverse events were significantly more in the tadalafil group (tadalafil vs placebo 14 adverse reactions [ADR] vs 5 ADR, P < .001).

The response of low-dose tadalafil on IIEF and FMD is largely similar to placebo; however, the utility of FMD% in young patients and placebo effect needs to be studied further. Pattanaik S, Kaundal P, Mavuduru RS, et al. Endothelial Dysfunction in Patients With Erectile Dysfunction: A Double-Blind, Randomized-Control Trial Using Tadalafil. Sex Med 2019;7:41-47.