1. Feldman HA, Goldstein I, Hatzichristou DG et al. Impotence and its medical and psychosocial correlates: results of the Massachusetts Male Aging Study. J Urol 1994; 151 (1): 54–61.
2. BenetA E, Melman A. The epidemiology of erectile dysfunction. Urol Clin North Am 1995; 22: 699–709.
3. Sand M. Men’s attitudes on life events and sexuality (MALES) survey. Presented at the 10 World Congress of the International Society for Sexual and Impotence Research, 26 September 2002, Montreal, Canada.
4. Block G et al. Efficacy and safety of Tadalafil for the treatment of erectile dysfunction: results of integrated analysis. J Urol 2002; 169 (4): 1332–6.
5. Bischoff E, Niewohner U, Haning H et al. The inhibitory selectivity of vardenafil on bovine and human recombinant phosphodiesterase isoenzymes. Int J Impot Res 2001; 13 (Suppl. 4): S41.
6. Stark S, Sachse R, Liedl T et al. Vardenafil increases penile rigidity and tumescence in men with erectile dysfunction after a single oral dose. Eur Urol 2001; 40: 181–90.
7. Block G. Oral Agents: First line therapy for erectile dysfunction. Eur Urol 2002; Suppl. 1: 12–8.
8. Udho Thadani, MD, FACC. Williams Smith, MD, FACC The Effect of Vardenafil, a potent and highly selective phosphodiesterase-5 inhibitor for the treatment of erectile dysfunction, on the cardiovascular response to exercise in patients with coronary artery disease. J Am Coll Cardiol 2002; 40 (11).
9. Gresser U, Gleiter CH. Erectile Dysfunction: comparison of efficacy and side effects of the PDE-5 inhibitors- Sildenafil? Vardenafil and Tadalafil. Review of literature. Eur J Med Res 2002; 7: 435–46.
10. Wayne JG et al. Tadalafil has no detrimental effect on human spermatogenesis or reproductive hormones. J Urol 2003; 170: 887–91.
11. Pradeep Agarwal, Sander GE, Giles TD. Treatment of Erectile Dysfunction in the Elderly With Phosphodiesterase Type 5 Inhibitors: Cardiovascular Implications. Am J Geriatric Cardiol 2004; 13 (6): 332–5.
12. Sandner P, Hutter J, Tinel H et al. PDE5 inhibitors beyond erectile dysfunction. Review. Int J Impot Res 2007; 19: 533–43.
13. Kloner RA, Jackson G, Hutter AM et al. Cardiovascular Safety Update of Tadalafil: Retrospective Analysis of Data from Placebo-Controlled and Open-Label Clinical Trials of Tadalafil With As Needed, Three Times-per-Week or Once-a-Day Dosing. Am J Cardiol 2006; 97: 1778–84.
14. Tinel H, Stelte-Ludwig B, Htter J, Sandner P. Pre-clinical evidence for the use of phosphodiesterase-5 inhibitors for treating benign prostatic hyperplasia and lower urinary tract symptoms. Bayer Health Care AG – Institute for Product-Related Research, Wuppertal, Germany. Accepted for publication 14 July 2006.
15. McVarya KT, Roehrborn CG, Kaminetsky JC et al. Tadalafil Relieves Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia. Materials of Elly Lilly company. 2006.
16. Fink HA, Mac Donald R, Rutks IR et al. Sildenafil for male erectile dysfunction: a systematic review and meta-analysis. Arch Intern Med 2002; 162: 1349–60.
17. Markou S, Perimenis P, Gyftopoulos K, et al. Vardenafil (Levitra) for erectile dysfunction: a systematic review and meta-analysis of clinical trial reports. IntJ Impot Res 2004.
18. Carson CC, Rajfer J, Eardley I et al. The efficacy and safety of tadalafil: an update. BJU Int 2004:93:1276-81.