A comparative study of terazosin and tamsulosin for symptomatic benign prostatic hyperplasia in Japanese patients

Objective To compare the efficacy and safety of an incremental-dose regimen of terazosin (1-2 mg daily) and a fixed-dose regimen of tamsulosin (0.2 mg daily), on Japanese patients with symptomatic benign prostatic hyperplasia (BPH). Patients and methods This multicentre, single-blind, randomized trial compa red terazosin and tamsulosin over 4 weeks, in 61 patients with symptomatic BPH randomly assigned to terazosin (n = 31) or tamsulosin (n = 30). Terazos in 0.5 mg twice daily was administered for 2 weeks, followed by 1 mg twice daily for 2 weeks. Tamsulosin (0.2 mg) was administered once daily for 4 we eks. Symptoms were evaluated using the International Prostate Symptom Score (IPSS), and quality of life (QOL) was assessed subjectively before treatme nt, and again after 2 and 4 weeks of treatment. Objective measurements take n before and after the treatment period were the maximum (Q(max)) and avera ge (Q(ave)) urinary flow rates, and the percentage residual urine volume. I mprovement was defined as a 25% decrease from baseline in IPSS, >1 point in crease in QOL score, and >2.5 mL/s increase in Q(max) Adverse reactions pot entially related to the study drugs were recorded throughout the treatment period. Results Both terazosin and tamsulosin produced statistically significant im provements in subjective and objective variables. Neither treatment affecte d systolic or diastolic blood pressure or pulse rate. Adverse reactions wer e noted in four patients (three in the terazosin group and one in the tamsu losin group). However, there was no statistically significant difference in the incidence of adverse effects between the groups. Conclusions Despite the limitations of small sample size and relatively sho rt treatment periods, terazosin and tamsulosin were equally effective In th e treatment of symptomatic BPH in Japanese patients, using relatively lower doses than those used in Western countries.