Abstract

Dutasteride is the first dual inhibitor of both 5alpha-reductase Types 1 and 2 isoenzymes, with efficacy and safety proven in 3 randomized placebo-controlled trials, each 2 years in duration. The current report demonstrates that longer-term treatment over 48 months with dutasteride results in continuing improvements in urinary symptoms and flow rate, and further reductions in total and transition zone volume of the prostate in men with symptomatic benign prostatic hyperplasia (BPH). The reduction in risk of acute urinary retention and BPH-related surgery, seen in the double-blind phase, was durable over the 4-year term of the studies. The incidence of new onset adverse events remained low during the open-label extension phase, and less than 1% of patients discontinued therapy due to adverse events. These findings combined establish that the disease-modifying benefits of dutasteride are durable in long-term treatment. Dutasteride was also well tolerated in long-term use, with no new safety issues emerging over 4 years of treatment.