A 3 MONTH DOUBLE-BLIND-STUDY OF DOXAZOSIN AS TREATMENT FOR BENIGN PROSTATIC BLADDER OUTLET OBSTRUCTION

Objective To evaluate the efficacy and tolerability of doxazosin in th e treatment of bladder outflow obstruction resulting from benign prost atic hyperplasia (BPH). Patients and methods One-hundred and thirty-fi ve patients with symptomatic urodynamically confirmed obstructive BPH were treated for 12 weeks with either doxazosin (67 patients) or place bo (68 patients) after an initial 2 week baseline evaluation. The main outcome measures were urodynamic and symptomatic evaluation for effic acy. Blood pressure and adverse events were monitored. Results Data we re obtained in 122 patients (60 doxazosin, 62 placebo). Doxazosin prod uced increases in bath mean and maximum urinary now rates of 1.01 ml/s and 3.2 ml/s respectively, compared with 0.21 ml/s and 2.2 ml/s on pl acebo. The increase in mean flow rate was statistically significant (P =0.04), while that for maximum flow rate approached significance (P= 0 .09). The maximum subtracted voiding pressure was substantially reduce d (P=0.007) and 19 of 53 (36%) patients had an increase in maximum flo w rate of 50% or more compared with 9 of 54 (17%) on placebo (P=0.024) . Twelve weeks' therapy with doxazosin resulted in significant improve ments (compared with placebo) in: hesitancy (doxazosin 26 of 46, place bo 11 of 43; P = 0.003), impaired urinary stream (doxazosin 31 of 55, placebo 16 of 48; P=0.019), nocturia (doxazosin 22 of 56, placebo 10 o f 54; P=0.017) and urgency (doxazosin 27 of 45, placebo 16 of 42; P= 0 .041). Frequency improved with doxazosin therapy (doxazosin 26 of 59, placebo 15 of 55; P=0.062). Adverse events, most frequently dizziness and headache, were usually mild and transient and led to a discontinua tion of doxazosin therapy in one patient. No clinically significant ch anges in sexual function or blood pressure were seen. Conclusion Doxaz osin was well-tolerated and produced both urodynamic and symptomatic i mprovement in men with BPH, thereby providing a satisfactory alternati ve to existing drugs with the additional benefit of once daily dosage.