Improvement in erection hardness and intercourse success with first dose of sildenafil citrate 100 mg

To determine, in men with erectile dysfunction (ED), the extent of improvement in erection hardness and in the rate of successful sexual intercourse (SSI) during the final intercourse attempt using sildenafil 50 mg compared with the subsequent initial attempt after a dose increase to 100 mg.

This post hoc analysis used data from two randomized, double-blind, placebo-controlled studies of flexible-dose sildenafil for the treatment of men with ED, who were given sildenafil 50 mg or matching placebo, to be taken as needed before sexual intercourse. After 2 weeks, those with no tolerability concerns were titrated up to 100 mg, forming the subgroup of this analysis. The main outcome measures were event log data, including an Erection Hardness Score (EHS) and a question on SSI ("Did your erection last long enough for you to have successful sexual intercourse?"), for each attempt at sexual intercourse, analyzed by study and treatment group (sildenafil or placebo). Statistical comparisons were conducted by using the Fisher's exact test.

In both studies, the sildenafil group had a larger proportion of EHS4 (completely hard and fully rigid) erections (P < 0.001) and SSI (P < 0.005) compared with the placebo group, both before and after the dose increase. Between the final 50 mg sildenafil dose and the initial 100 mg sildenafil dose, the outcomes improved and significantly so in the larger study.

The improved efficacy with sildenafil 100 mg versus 50 mg, which occurs rapidly, suggests that patients should be encouraged to use 100 mg if they are unable to achieve completely hard and fully rigid erections or SSI with the 50 mg dose.