Category: Articles

Discussion. Sildenafil (Viagra): a meta-analysis of clinical trial reports

This review demonstrated that considerable amounts of useful information are available in clinical trial reports submitted for marketing authorisation (licensing). That information adequately describes research methods used, though could be improved, perhaps using the updated CONSORT criteria. If these guidelines are becoming necessary for publication of randomised trials in our major medical journals, then they […]

Sildenafil (Viagra) for male erectile dysfunction: Results Of meta-analysis

Efficacy The efficacy results closest to the prior definition of efficacy of a man with the consistent three part outcome, consisting of an erection, sufficiently rigid for penetration, and followed by successful intercourse were the number of men in whom at least 60% or at least 40% of attempts at sexual intercourse were successful. The […]

Sildenafil (Viagra) for male erectile dysfunction: Results

Twenty-seven clinical trial reports were made available, all prepared for a marketing authorisation application, and dated September 1997. Some of these were single dose use in laboratory setting with penile plethysmography as an outcome. Others were open extensions of randomised studies. These were not useful, and 17 were excluded; details of excluded studies and reasons […]

Sildenafil (Viagra): a meta-analysis of clinical trial reports: Methods

No search strategy was required because this review was of material made available by Pfizer UK Ltd in the form of clinical trial reports used in a marketing authorisation application for sildenafil (Viagra) in September 1997. QUORUM guidelines were otherwise followed. The prior intention was to use studies that were relevant to the use of […]

Sildenafil (Viagra) for male erectile dysfunction: a meta-analysis of clinical trial reports

Meta-analyses that include otherwise unpublished randomised trials are uncommon, but are welcome, and can inform in circumstances where information is contradictory. The example of generic tramadol in acute pain, where information on 3,500 patients was made available, explained the results of two studies, one showing that tramadol was a highly efficacious analgesic, the other showing […]


Viagra (Sildenafil) has been approved in over 50 countries. As of November 1998, 6.4 million prescriptions had been filled within the United States, representing over 50 million tablets dispensed. This equates to over 3.5 million men and corresponds to a cumulative exposure of 25 million man-weeks since the drug was launched in April 1998. To […]


Patients with erectile dysfunction and no history of eye disorder are described in detail elsewhere. Morales and associates have summarized the clinical safety of sildenafil in phase II/II clinical trials. In 6 flexible-dose studies comparing the efficacy of sildenafil (734 patients) with placebo (725 patients), abnormal vision was reported by 3% of those treated with […]