In data pooled from 6 parallel-group , fixed-dose trials , efficacy appeared slightly greater at higher doses .
Treatment response appeared to vary between patient subgroups , although relative to placebo , sildenafil significantly improved erectile function in all evaluated subgroups .
In trials with parallel-group design and flexible dosing , men r and omized to receive sildenafil were less likely than those receiving placebo to drop out for any reason and no more likely to drop out due to an adverse event or laboratory abnormality .
Sildenafil was not significantly associated with serious cardiovascular events or death .
CONCLUSIONS Sildenafil improves erectile function and is generally well tolerated .
Treatment response seems to vary between patient subgroups , although sildenafil has greater efficacy than placebo in all evaluated subgroups
OBJECTIVE To determine the efficacy and safety of sildenafil citrate in the treatment of male erectile dysfunction .
Oral sildenafil in the treatment of erectile dysfunction. Sildenafil Study Group.
BACKGROUND Sildenafil is a potent inhibitor of cyclic guanosine monophosphate hydrolysis [ corrected ] in the corpus cavernosum and therefore increases the penile response to sexual stimulation . We evaluated the efficacy and safety of sildenafil , administered as needed in two sequential double-blind studies of men with erectile dysfunction of organic , psychogenic , and mixed causes . METHODS In a 24-week dose-response study , 532 men were treated with oral sildenafil  ( 25 , 50 , or 100 mg ) or placebo . In a 12-week , flexible dose-escalation study , 329 different men were treated with sildenafil or placebo , with dose escalation to 100 mg based on efficacy and tolerance . After this dose-escalation study , 225 of the 329 men entered a 32-week , open-label extension study . We assessed efficacy according to the International Index of Erectile Function , a patient log , and a global-efficacy question . RESULTS In the dose-response study , increasing doses of sildenafil were associated with improved erectile function ( P values for increases in scores for questions about achieving and maintaining erections were < 0.001 ) . For the men receiving 100 mg of sildenafil , the mean score for the question about achieving erections was 100 percent higher after treatment than at base line ( 4.0 vs. 2.0 of a possible score of 5 ) . In the last four weeks of treatment in the dose-escalation study , 69 percent of all attempts at sexual intercourse were successful for the men receiving sildenafil , as compared with 22 percent for those receiving placebo ( P<0.001 ) . The mean numbers of successful attempts per month were 5.9 for the men receiving sildenafil and 1.5 for those receiving placebo ( P<0.001 ) . Headache , flushing , and dyspepsia were the most common adverse effects in the dose-escalation study , occurring in 6 percent to 18 percent of the men . Ninety-two percent of the men completed the 32-week extension study . CONCLUSIONS Oral sildenafil is an effective , well-tolerated treatment for men with erectile dysfunction
In data pooled from 6 parallel-group , fixed-dose trials , efficacy appeared slightly greater at higher doses .
Treatment response appeared to vary between patient subgroups , although relative to placebo , sildenafil significantly improved erectile function in all evaluated subgroups .
In trials with parallel-group design and flexible dosing , men r and omized to receive sildenafil were less likely than those receiving placebo to drop out for any reason and no more likely to drop out due to an adverse event or laboratory abnormality .
Sildenafil was not significantly associated with serious cardiovascular events or death .
CONCLUSIONS Sildenafil improves erectile function and is generally well tolerated .
Treatment response seems to vary between patient subgroups , although sildenafil has greater efficacy than placebo in all evaluated subgroups
OBJECTIVE To determine the efficacy and safety of sildenafil citrate in the treatment of male erectile dysfunction .