A large retrospective analysis of acute urinary retention and prostate-related surgery in BPH patients treated with 5-alpha reductase inhibitors: dutasteride versus finasteride

Abstract

Objective: The purpose of this study was to examine the rates of acute urinary retention (AUR) and surgery after initiating 5-alpha reductase inhibitor (5ARI) therapy and to compare the 2 currently available 5ARIs, dutasteride and finasteride, in a real-world, managed care setting. This study constitutes the first direct comparison of therapeutic outcome between a mono 5ARI (finasteride) and a dual 5ARI (dutasteride).

Methods: This is a retrospective descriptive and comparative analysis of the rates of AUR and prostate surgery in patients with benign prostatic hyperplasia (BPH) treated with 5ARI therapy, either dutasteride or finasteride. Data were obtained from the PharMetrics Integrated Medical and Pharmaceutical Database (PIMPD) (Watertown, Mass) during a 6-year period. The PIMPD is a large national healthcare database that represents a total of 85 managed health plans and covers more than 45 million patients. The data analysis included all patients aged 50 years or older diagnosed with BPH who were treated with 5ARIs (dutasteride 0.5 mg/day or finasteride 5 mg/day) for up to 12 months during the 6-year period of January 1, 1999, to March 1, 2005. Patients meeting the selection criteria were evaluated for a total of 12 months with regard to the likelihood of experiencing AUR or prostate-related surgery.

Results: After 5 months of 5ARI therapy, the rate of AUR during months 5 to 12 was found to be significantly lower in the dutasteride group compared with the finasteride group (5.3% vs 8.3%). After controlling for background covariates, dutasteride-treated patients were 49.1% less likely to experience AUR than patients treated with finasteride (P = .0207). Patients treated with dutasteride were also less likely to undergo prostate-related surgery, with 1.4% of dutasteride treated patients and 3.4% of patients receiving finasteride undergoing surgery; differences in surgery rates, however, were not statistically significant (P = .0745), even after controlling for background covariates. CONCLUSTION: Although the 2 drugs, dutasteride and finasteride, belong to the same category of 5ARIs, this large retrospective multivariate analysis potentially indicates differences in therapeutic outcomes. In this study, patients treated with dutasteride were less likely to experience AUR and demonstrated a trend toward being less likely to experience surgery than patients treated with finasteride.