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Tadalafil dosed once a day in men with erectile dysfunction: a randomized, double-blind, placebo-controlled study in the US

Abstract

The efficacy and safety of tadalafil, dosed once a day for the treatment of erectile dysfunction, was assessed in a randomized, double-blind, placebo-controlled, parallel-design study at 15 US centers. Following a 4-week treatment-free run-in period, patients (18 years of age) were randomly assigned to 24 weeks treatment with tadalafil 2.5 mg, tadalafil 5 mg or placebo. Primary efficacy endpoints were change at 24 weeks in International Index of Erectile Function Erectile Function (EF) Domain score and mean per-patient percentage ‘yes’ responses to Sexual Encounter Profile diary questions 2 and 3. Tadalafil significantly improved erectile function compared with placebo for all three co-primary efficacy endpoints. Few patients discontinued because of adverse events (2.1%, placebo; 6.3%, tadalafil 2.5 mg; 4.1%, tadalafil 5 mg). Common treatment-emergent adverse events (5%) were nasopharyngitis, influenza, viral gastroenteritis and back pain. Tadalafil 2.5 mg and 5 mg, dosed once a day for 24 weeks, was well tolerated and significantly improved erectile function.

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References

  1. National Institutes of Health Consensus Statement on Impotence, December, 1992. JAMA 1993; 270: 83–90.

  2. Goldstein I, Lue TF, Padma-Nathan H, Rosen RC, Steers WD, Wicker PA . Oral sildenafil in the treatment of erectile dysfunction. Sildenafil Study Group. N Engl J Med 1998; 338: 1397–1404 (Erratum in N Engl J Med 1998; 339: 59).

    CAS  Article  Google Scholar 

  3. Porst H, Rosen R, Padma-Nathan H, Goldstein I, Giuliano F, Ulbrich E et al. The efficacy and tolerability of vardenafil, a new, oral, selective phosphodiesterase type 5 inhibitor, in patients with erectile dysfunction: the first at-home clinical trial. Int J Impot Res 2001; 13: 192–199.

    CAS  Article  Google Scholar 

  4. Padma-Nathan H, McMurray JG, Pullman WE, Whitaker JS, Saoud JB, Ferguson KM et al. On-demand IC351 (Cialis) enhances erectile function in patients with erectile dysfunction. Int J Impot Res 2001; 13: 2–9.

    CAS  Article  Google Scholar 

  5. Hatzimouratidis K, Hatzichristou DG . A comparative review of the options for treatment of erectile dysfunction, which treatment for which patient? Drugs 2005; 65: 1621–1650.

    CAS  Article  Google Scholar 

  6. Porst H, Padma-Nathan H, Giuliano F, Anglin G, Varanese L, Rosen R . Efficacy of tadalafil for the treatment of erectile dysfunction at 24 and 36 h after dosing: a randomized controlled trial. Urology 2003; 62: 121–125.

    Article  Google Scholar 

  7. Young JM, Feldman RA, Auerbach SM, Kaufman JM, Garcia CS, Shen W et al. Tadalafil improved erectile function at twenty-four and thirty-six hours after dosing in men with erectile dysfunction: US trial. J Androl 2005; 26: 310–318.

    CAS  Article  Google Scholar 

  8. Forgue ST, Patterson BE, Bedding AW, Payne CD, Phillips DL, Wrishko RE et al. Tadalafil pharmacokinetics in healthy subjects. Br J Clin Pharmacol 2005; 61: 280–288.

    Article  Google Scholar 

  9. McMahon C . Efficacy and safety of daily tadalafil in men with erectile dysfunction previously unresponsive to on-demand tadalafil. J Sex Med 2004; 1: 292–300.

    CAS  Article  Google Scholar 

  10. McMahon C . Comparison of efficacy, safety, and tolerability of on-demand tadalafil and daily dosed tadalafil for the treatment of erectile dysfunction. J Sex Med 2005; 2: 415–427.

    CAS  Article  Google Scholar 

  11. Porst H, Giuliano F, Glina S, Ralph D, Casabé AR, Elion-Mboussa A et al. Evaluation of the efficacy and safety of daily dosing of tadalafil 5 mg and 10 mg in the treatment of erectile dysfunction: results of a multicenter, randomized, double-blind, placebo-controlled trial. Eur Urol 2006 (in press).

  12. Rosen RC, Riley A, Wagner G, Osterloh IH, Kirkpatrick J, Mishra A . The International Index of Erectile Function (IIEF): a multidimensional scale for the assessment of erectile dysfunction. Urology 1997; 49: 822–830.

    CAS  Article  Google Scholar 

  13. Swindle RW, Cameron AE, Lockhart DC, Rosen RC . The psychological and interpersonal relationship scales: assessing psychological and relationship outcomes associated with erectile dysfunction and its treatment. Arch Sex Behav 2004; 33: 19–30.

    Article  Google Scholar 

  14. Brock GB, McMahon CG, Chen KK, Costigan T, Shen W, Watkins VS et al. Efficacy and safety of tadalafil in the treatment of erectile dysfunction: results of integrated analyses. J Urol 2002; 168: 1332–1336 (Erratum in J Urol 2005; 173: 664).

    CAS  Article  Google Scholar 

  15. Rosen R, Broderick G, Shabsigh R, Swindle R, Lockhart D, Cameron A . Sensitivity of the psychological and interpersonal relationship scales to oral therapies for erectile dysfunction. J Sex Med 2005; 2: 461–468.

    Article  Google Scholar 

  16. Dean J, Hackett G, Vincenzo G, Pirozzi Farina F, Rosen RC, Zhao Y et al. Psychosocial outcomes and drug attributes affecting treatment choice in men receiving sildenafil citrate and tadalafil for the treatment of erectile dysfunction in an open label, randomized, multicenter, crossover study. J Sex Med 2006; 3: 650–661.

    CAS  Article  Google Scholar 

  17. Swindle R, Cameron A, Rosen R . A 15-item short form of the psychological and interpersonal relationship scales. Int J Impot Res 2006; 18: 82–88.

    CAS  Article  Google Scholar 

  18. Vernet D, Magee TR, Qian A, Nolazco G, Rajfer J, Gonzalez-Cadavid NF . Phosphodiesterase type 5 is not upregulated by tadalafil in cultures of human penile cells. J Sex Med 2006; 3: 84–95.

    CAS  Article  Google Scholar 

  19. Ferrini MG, Valente EG, Rajfer J, Gonzolez-Cadavid NF . Long-term treatment with high doses of sildenafil does not up-regulate the levels of phosphodiesterase 5 (PDE5) in the rat penis. J Urol 2004; 171 (Suppl 4): 424.

    Article  Google Scholar 

  20. Musicki B, Champion HC, Becker RE, Kramer MF, Liu T, Sezen SF et al. In vivo analysis of chronic phosphodiesterase-5 inhibition with sildenafil in penile erectile tissues: no tachyphylaxis effect. J Urol 2005; 174: 1493–1496.

    CAS  Article  Google Scholar 

  21. Lin G, Xin ZC, Lue TF, Lin CS . Up and down-regulation of phosphodiesterase-5 as related to tachyphylaxis and priapism. J Urol 2003; 170: S15–S18.

    Article  Google Scholar 

  22. McMahon CG, Carson CC, Fischer CJ, Wang WC, Florio VA, Bradley JD . Tolerance to the therapeutic effect of tadalafil does not occur during 6 months of treatment: a randomized, double-blind, placebo-controlled study in men with erectile dysfunction. J Sex Med 2006; 3: 504–511.

    CAS  Article  Google Scholar 

  23. Carson CC, Rajfer J, Eardley I, Carrier S, Denne JS, Walker DJ et al. The efficacy and safety of tadalafil: an update. BJU Int 2004; 93: 1276–1281.

    CAS  Article  Google Scholar 

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Acknowledgements

We acknowledge the additional study investigators: Stephen Auerbach, MD; Bradley Davis, MD; Eugene Dula, MD; Robert Feldman, MD; Darrell N. Fiske, MD; Michael Gambla, MD; Joel Kaufman, MD; Ira Klimberg, MD; Gary Ruoff, MD; David R Talley, MD; and Jay Young, MD. We thank Kate Loughney, PhD, ICOS Corporation for help in preparation of the manuscript and Steven D Watts, MS, Eli Lilly and Company for statistical analyses.

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Correspondence to J Rajfer.

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Disclosure

Study (study code H6D-MC-LVFP) funded by Lilly ICOS LLC.

Conflict of Interest Statements

Dr J Rajfer

Grants, Advisory Board, and Consultant for Lilly ICOS LLC, Pfizer, Bayer, Glaxo SmithKline.

Dr PJ Aliotta

Principal Investigator, Speaker, and Consultant for Lilly ICOS LLC, Pfizer, Glaxo SmithKline, Watson Pharmaceuticals, Novartis, Schering Plough; Principal Investigator and Consultant for Alza Pharmaceuticals, Speaker and Consultant for Boehringer Ingelheim and Ortho McNeil Pharmaceuticals.

Dr CP Steidle

Speaker and consultant for Lilly ICOS LLC, Speaker and Investigator for Pfizer, Bayer GSK.

Dr WP Fitch III

Speaker, Grant Support, Consultant for Lilly ICOS LLC, Speaker and Grant Support for Glaxo SmithKline, Grant Support from Johnson and Johnson.

Dr Y Zhao

Employee, Eli Lilly and Company.

Dr A Yu

Employee, ICOS Corporation.

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Rajfer, J., Aliotta, P., Steidle, C. et al. Tadalafil dosed once a day in men with erectile dysfunction: a randomized, double-blind, placebo-controlled study in the US. Int J Impot Res 19, 95–103 (2007). https://doi.org/10.1038/sj.ijir.3901496

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  • DOI: https://doi.org/10.1038/sj.ijir.3901496

Keywords

  • erectile dysfunction
  • tadalafil
  • PDE5 inhibitor

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