Comparison of prazosin, terazosin and tamsulosin in the treatment of symptomatic benign prostatic hyperplasia: a short-term open, randomized multicenter study. BPH Medical Therapy Study Group. Benign prostatic hyperplasia.

Background: The objective of this open randomized clinical study was to compare the short-term efficacy and safety of three alpha-1 blockers, prazosin, terazosin and tamsulosin, in the treatment of lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH).

Methods: The study comprised 121 patients with symptomatic BPH who were randomized to receive 0.5 mg of prazosin twice daily, 0.5 mg of terazosin twice daily or 0.1 mg of tamsulosin once daily for the initial 2 weeks. The doses were doubled for the next 2 weeks. The primary variables assessed were a symptom score, changes in maximum and average urinary flow rate (Qmax and Qave), postvoid residual urine volume and blood pressure.

Results: The percentage changes in the total symptom score from baseline were 38, 39 and 26% at 4 weeks by prazosin, terazosin and tamsulosin, respectively. Terazosin produced significantly higher improvement in four out of nine individual symptoms than tamsulosin (P < 0.05). A significant increase in Qmax or Qave in uroflowmetry was obtained in the prazosin and tamsulosin groups. Blood pressure remained unchanged in normotensive patients, but significantly decreased in hypertensive patients except for the tamsulosin group. Adverse events were minimal in all treatment groups.

Conclusions: The efficacy and safety profiles were different among the alpha-1 blockers at standard doses. Tamsulosin appears to be safer than the others for aged patients or patients with hypertension who have impaired blood pressure regulation, while terazosin is significantly effective in improving symptomatic score when compared with the others examined. It is recommended that the alpha-1 blocking agent and its optimal dose are selected on the basis of the baseline characteristics of the patients with symptomatic BPH.