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

Tadalafil treatment significantly improved SEP3 and IIEF EF domain scores. The efficacy of tadalafil, taken as needed, was maintained over a 6‐month treatment period in men with ED. McMahon CG, Carson CC, Fischer CJ, Wang WC, Florio VA, and 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.