Maximum Efficacy of Finasteride Is Obtained within 6 Months and Maintained over 6 Years

Abstract

Objectives: To study the long-term efficacy and safety of the drug finasteride (Proscar^®) for benign prostatic hyperplasia and to evaluate whether an improved effect beyond 1 year was due to continuous selection of ‘responders’. We also wanted to investigate whether drop-outs differed in short-term responses to those completing the trial. Methods: A total of 182 patients were enrolled in a double-blind randomized multicenter study with the drug finasteride. After 6 months, all patients were treated with active drug for up to 6 years. Ninety-nine of the patients (54.5%) were still in the trial at its closure. Results: Patients treated with active drug had a decrease in prostate size of around 27% at 6 months, a figure reached by the ex-placebo group at 12 months. At 6 years, both groups had a reduction in prostate size of 21% as measured from baseline. At 6 months, urinary flow had improved by a mean of 2.4 ml/s in the finasteride group and reached an improvement of 2.8 ml/s in the ex-placebo group at 12 months. At 6 years, the flow had improved by 2.2 ml/s in both groups combined as compared to baseline data. The symptom score was improved by 3.4 points in the finasteride group at 6 months and by 2.6 points in the ex-placebo group at 12 months; both values were then maintained over 6 years. Conclusion: In responders (those completing the 6-year trial), finasteride appeared to be a safe drug which reduced the prostate size by 20–25% within 6 months, with a simultaneous 30% improvement of objective and subjective symptoms and a 2.2 ml/s improvement in urinary flow rate. The improvements were maintained for at least 6 years; however, further improvement beyond 6 months of therapy was not likely to occur.