title: Long-term sustained improvement in symptoms of benign prostatic hyperplasia with the dual 5alpha-reductase inhibitor dutasteride: results of 4-year studies.
abstract: OBJECTIVE
  To report additional analyses of efficacy over the initial 2 years and during a 2-year open-label extension of the three pivotal phase 3 studies in which dutasteride, a dual inhibitor of type 1 and 2 5alpha-reductase, was shown to be effective and well tolerated.
  
  
  METHODS
  All patients in the placebo and active groups were eligible for entry into the 2-year open-label extension, with all receiving dutasteride 0.5 mg daily. Mean changes from baseline were calculated for the American Urologic Association Symptom Index (AUA-SI) score at each scheduled time in the double-blind and open-label phase. The additional analyses included a breakdown of the AUA-SI score, including stratifying patients by symptom severity, assessment by baseline age and prostate volume, and the evaluation of symptoms responders.
  
  
  RESULTS
  There was a clinically meaningful improvement in AUA-SI in patients on dutasteride in the double-blind phase, but not in those on placebo. At 48 months, patients on dutasteride in both study phases had greater improvements in AUA-SI score and individual question scores than those on dutasteride in the open-label phase only. The proportion of patients with severe symptoms declined in both study groups, although these changes were more profound in those receiving dutasteride for the 4-year duration of the study.
  
  
  CONCLUSIONS
  In men with symptomatic benign prostatic hyperplasia, long-term (4-year) treatment with the dual isozyme 5alpha-reductase inhibitor dutasteride resulted in sustained and continued improvements in symptoms and flow rate. For 4 vs 2 years, longer dutasteride therapy resulted in greater symptom improvement.
authors.affiliation: Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9110, USA. Claus.Roehrborn@UTSouthwestern.edu
authors.forename: Claus G
authors.initials: CG
authors.lastname: Roehrborn
authors.forename: Olavi
authors.initials: O
authors.lastname: Lukkarinen
authors.forename: Stephen
authors.initials: S
authors.lastname: Mark
authors.forename: Paul
authors.initials: P
authors.lastname: Siami
authors.forename: Joe
authors.initials: J
authors.lastname: Ramsdell
authors.forename: Norman
authors.initials: N
authors.lastname: Zinner
mesh_terms: D058891:5-alpha Reductase Inhibitors; D000368:Aged; D001378:Azasteroids / Q000627:therapeutic use*; D004311:Double-Blind Method; D000068538:Dutasteride; D005500:Follow-Up Studies; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D008297:Male; D008875:Middle Aged; D011470:Prostatic Hyperplasia / Q000188:drug therapy*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D058891:5-alpha Reductase Inhibitors; D001378:Azasteroids; D007527:Isoenzymes; D000068538:Dutasteride