Long-term efficacy and safety of terazosin in patients with benign prostatic hyperplasia. Terazosin Research Group.
To evaluate long-term efficacy and safety of terazosin, a selective alpha 1 blocker, in the treatment of benign prostatic hyperplasia (BPH). This was a long-term (42 months), open-label, multicenter study with patients evaluated at 1- to 6-month intervals. Twenty-three outpatient clinics throughout the United States and Canada participated in the study. A total of 494 men with symptomatic BPH, lacking absolute indications for surgery, were enrolled in this study; 298 were transferred into the study from randomized, placebo-controlled studies of terazosin and 196 had no prior terazosin therapy. Terazosin was given starting at 1 mg/d and titrated upward until symptoms were relieved or a maximum dose of 20 mg/d was achieved, whichever came first. Peak urinary flow rates at all visits were significantly higher than baseline values, with mean improvements ranging from 1.0 to 4.0 mL/s. At 3 months, 40% of patients exhibited a 30% or greater improvement in peak flow rate; this improvement was maintained through 42 months. Boyarsky symptom scores improved significantly at all visits; mean total score improved by at least 4.0 points (40%) at all visits beyond 3 months. The most common adverse events resulting in premature termination from the study were dizziness (6.7%), asthenia (3.8%), and somnolence (2.0%). This study suggests that terazosin is well tolerated and effective in longterm treatment of patients with BPH.