PURPOSE: Tadalafil has regulatory approval for the treatment of men with signs/symptoms of benign prostatic hyperplasia with and without erectile dysfunction.
We assessed whether the effects of treatment with tadalafil for lower urinary tract symptoms/benign prostatic hyperplasia are independent of improvements in erectile dysfunction.
MATERIALS AND METHODS: Four separate analyses used integrated data from 4 randomized, double-blind, placebo controlled studies in men with lower urinary tract symptoms/benign prostatic hyperplasia with and without erectile dysfunction to test whether total I-PSS (International Prostate Symptom Score) improvement was due to improvement in IIEF-EF (International Index of Erectile Function-Erectile Function domain score). Unidirectional and bidirectional path analysis models determined direct and indirect treatment effects mediated by improvements in lower urinary tract symptoms/benign prostatic hyperplasia and erectile dysfunction symptoms.
RESULTS: A total of 1,496 men, of whom 77% had erectile dysfunction, received at least 1 dose of tadalafil 5 mg once daily or placebo. The placebo adjusted treatment effect for men with erectile dysfunction was represented by a mean decrease of -2.3 (p < 0.0001) in total I-PSS vs -2.2 (p = 0.0007) for men without erectile dysfunction. The correlation between change from baseline in total I-PSS and IIEF-EF was weak (r2 = 0.08, p < 0.0001). The unidirectional path analysis model suggested that the total treatment effect on total I-PSS score improvement (2.25) was derived from a direct treatment effect of 1.57 (70%, p < 0.001) and an indirect treatment effect of 0.67 (30% via IIEF-EF improvement, p <0.001). Bidirectional path analysis showed that total I-PSS improvement was largely attributed to direct (92.5%, p < 0.001) vs indirect (7.5%, p = 0.32) treatment effects via IIEF-EF improvement.
CONCLUSIONS: Regardless of the analytical approach, self-reported erectile dysfunction status did not appreciably influence tadalafil treatment response in men with lower urinary tract symptoms/benign prostatic hyperplasia, supporting the dual action of tadalafil on lower urinary tract symptoms/benign prostatic hyperplasia and erectile dysfunction.
Written by:
Brock GB, McVary KT, Roehrborn CG, Watts S, Ni X, Viktrup L, Wong DG, Donatucci C. Are you the author?
University of Western Ontario, London, Ontario, Canada.
Reference: J Urol. 2013 Oct 1. pii: S0022-5347(13)05556-0.
doi: 10.1016/j.juro.2013.09.057
PubMed Abstract
PMID: 24096120
