α1-blocker tamsulosin as initial treatment for patients with benign prostatic hyperplasia: 5-year outcome analysis of a prospective multicenter study

Objective To comprehensively analyze the 5-year outcomes of tamsulosin treatment for patients with benign prostatic hyperplasia. Methods Tamsulosin (0.2 mg/day) was given to 112 patients who had International Prostate Symptom Scores ≥8. They were prospectively followed for 5 years with periodic evaluation. If tamsulosin had to be discontinued, the reason was determined. Treatment failure was considered in the case of disease progression (postvoid residual urine volume ≥200 mL, acute urinary retention, febrile urinary tract infection or hydronephrosis as a result of bladder outlet obstruction), conversion to other α1-blockers or need for surgery. An intention-to-treat analysis was carried out. Results A total of 34 patients (30.4%) continued the same medication for the overall study period, whereas 78 patients (69.6%) discontinued the medication. International Prostate Symptom Scores, Benign Prostatic Hyperplasia Problem Index and Quality of Life Index were significantly improved over the 5-year period. Treatment failure was observed in 21 patients (18.8%). Baseline prostate volume and postvoid residual urine volume were independent factors to predicting treatment failure. A total of 21 patients (18.8%) discontinued tamsulosin because of an improvement of symptoms. They were younger and had lower prostate-specific antigen levels than the remaining 91 patients. Their symptoms were stable even 1 year after termination of therapy. Conclusions Long-term efficacy of tamsulosin was observed, although only a small portion of patients continued the treatment. α1-blocker monotherapy might be not appropriate for achieving a good long-term outcome in patients with a large prostate volume and a large amount of postvoid residual urine volume. Persistent improvement of symptoms, even after termination of tamsulosin, was observed in young patients with low prostate-specific antigen levels.