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Sildenafil citrate efficacy 8 h postdose in men with mild to moderate erectile dysfunction


In two randomized, double-blind, placebo-controlled trials of 100 mg sildenafil citrate, men (N=601) with mild to moderate erectile dysfunction (ED) attempted intercourse 8 h (range, 7–9 h) postdose. The baseline to end-of-treatment improvement in the sildenafil groups vs placebo was greater (P<0.001) for the per-patient proportion (PPP) of ‘yes’ responses to the Sexual Encounter Profile question 3 (SEP3: successful intercourse (primary outcome)) (odds ratio (OR)=3.2 (trial 1), 7.6 (trial 2) and 5.6 (pooled data)); PPP of erection hardness score 4 (EHS 4, completely hard and fully rigid) (OR=6.2 (trial 1) and 10.9 (trial 2)); scores on the International Index of Erectile Function; and other EHS and SEP outcomes. Two to three times as many men were satisfied with sildenafil vs placebo treatment (Erectile Dysfunction Inventory of Treatment Satisfaction Index >50). Thus, responsiveness to 100 mg sildenafil may persist for 8 h postdose in men with mild to moderate ED.

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Study investigators included Connie Abarikwu, Stephen Auerbach, James Bailen, Martin Bastuba, David Bilhartz, Orpheus Bizzozero Jr, Joseph Camps Jr, Michael Collins, Lawrence Feldman, Robert Feldman, Sheldon Freedman, Evan Goldfischer, Gerard Henry, Adrian James, Jed Kaminetsky, Joel Kaufman, Edward Loizides, Andrew McCullough, James McMurray, Marcia Miller, Simon Mirelman, William Monnig, William Moseley Jr, Patrick Ogilvie, Terri Oskin, Juan Otheguy, Harin Padma-Nathan, Walter Pittman, Steven Rosenberg, Randolph Ross, Jose Sotolongo Jr, Christopher Steidle, Mark Swierzewski and David Talley. The studies were funded by Pfizer Inc. Editorial assistance was provided by Deborah M Campoli-Richards, BSPHA, RPh, and Nancy E Price, PhD, of Complete Healthcare Communications Inc., and was funded by Pfizer Inc.

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Correspondence to A R McCullough.

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Conflict of interest

Andrew McCullough has been a consultant, investigator, lecturer and/or Advisory Board member for Auxillium Pharmaceuticals, Bayer-GSK, Guilford Pharmaceuticals, Ion Channel, Johnson & Johnson, Lilly-ICOS, Pfizer and Schering Plough; Christopher P Steidle has been a lecturer for Astellas Pharma, Auxillium Pharmaceuticals Pfizer and Solvay Pharmaceuticals. Joel Kaufman has been a consultant, lecturer, trial investigator and/or on the Speakers’ Bureau for Amgen, Astellas Pharma, Coloplast, Indevus Pharmaceuticals, Lilly, Novartis Pharmaceuticals, Pfizer and Solvay Pharmaceuticals. Evan R Goldfischer has been a consultant, investigator and/or lecturer for Amgen, Astellis Pharma, Auxillium Pharmaceuticals, Bayer-GSK, Indevus Pharmaceuticals, Johnson & Johnson, Lilly, Merck & Co., Novartis Pharmaceuticals, Ortho McNeil Pharmaceutical, Pfizer, Sanofi-Aventis, Schering Plough and Schwartz. Brian Klee and Martin Carlsson are employees of Pfizer lnc.

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McCullough, A., Steidle, C., Kaufman, J. et al. Sildenafil citrate efficacy 8 h postdose in men with mild to moderate erectile dysfunction. Int J Impot Res 20, 388–395 (2008).

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  • erectile dysfunction
  • sildenafil citrate
  • duration of activity


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