Pfizer Canada Inc. responded to my initial request1 1 month after it was mailed. Three other companies replied more rapidly, but most took longer than Pfizer Canada; relatively speaking, Pfizer Canada's response was prompt. In its response, Pfizer Canada did list all of the relevant trials, but 3 additional papers were listed that did not fulfil the criteria in my request. One was an uncontrolled nonblinded trial,2 the second was a retrospective subanalysis of data from double-blind, placebo-controlled studies3 and the third analyzed safety and tolerability data from a series of double-blind, placebo-controlled studies and open-label extension studies.4
Joel Lexchin Emergency Physician University Health Network Toronto, Ont.
References
- 1.Lexchin J. Inaccessibility of drug reports [letter]. CMAJ 2002;166(10):1251. [PMC free article] [PubMed]
- 2.Boolell M, Allen MJ, Ballard SA, Gepi-Attee S, Muirhead GJ, Naylor AM, et al. Sildenafil, a novel effective oral therapy for male erectile dysfunction. Br J Urol 1996;78:257-61. [DOI] [PubMed]
- 3.Conti CR, Pepine CJ, Sweeney M. Efficacy and safety of sildenafil citrate in the treatment of erectile dysfunction in patients with ischemic heart disease. Am J Cardiol 1999;83:29C-34C. [DOI] [PubMed]
- 4.Morales A, Gingell C, Collins M, Wicher PA, Osterloh IH. Clinical safety of oral sildenafil citrate (Viagra) in the treatment of erectile dysfunction. Int J Impot Res 1998;10:69-74. [DOI] [PubMed]