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 [...]

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 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 [...]

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 [...]

Meta-analyses that include otherwise unpublished randomised trials are uncommon, but are welcome, and can inform in circumstances where information is contradictory.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 [...]

Cognizant of the preclinical data, substantial efforts were made to investigate the visual effects of sildenafil during clinical development. A number of Phase II and III studies were carried out to determine the safety of sildenafil in relation to the retina and visual function. Much of the data, with complete study descriptions, will appear in [...]

Early in preclinical development, it was found that sildenafil inhibits retinal PDE6 enzymes with an IC50 of 27-58 nM. Although this was substantially less than its effect on the intended target, PDE5 (IC50 3.9 nM), it led to the evaluation of safety of high doses of sildenafil on retinal histopathology in rats and dogs and [...]