A double-blind placebo-controlled study evaluating the onset of action of doxazosin gastrointestinal therapeutic system in the treatment of benign prostatic hyperplasia.

OBJECTIVE

To determine the onset of improvement in benign prostatic hyperplasia symptoms in patients after treatment with doxazosin gastrointestinal therapeutic system (DOX GITS) versus placebo.

METHODS

In this prospective, randomized, double-blind, placebo-controlled trial, baseline values, including International Prostate Symptom Score (IPSS) and maximum urine flow rate (Q(max)), were determined following a 2-week placebo run-in. Patients received DOX GITS 4 mg/d (n = 108) or placebo (n = 105) for 14 days. IPSS was measured on Days 3, 7, and 14; Q(max) on Days 1, 3, 7, and 14; and the patients' perception of improvement was measured on Days 1 and 2 in the evening at home and in the office on Day 14.

RESULTS

Significantly more patients treated with DOX GITS than placebo perceived improvement after Day 1 (60.6% vs. 41.9%) through Day 14 (84.3% vs. 64.1%). On Day 1, improvement in Q(max) with DOX GITS was not significantly different compared with placebo. On Day 3 of the trial (1) IPSS improvement was significantly greater with DOX GITS than with placebo; (2) proportion of patients with > or =30% improvement in IPSS was significantly greater with DOX GITS (49.5%) than placebo (28.4%) and remained so through Day 14; (3) improvement in Q(max) was significantly greater with DOX GITS (3.7 mL/s) than placebo (1.9 mL/s) and remained so through Day 14; (4) proportion of patients with > or =3 mL/s increase in Q(max) was statistically greater with DOX GITS (54.4%) versus placebo (30.8%) and remained so through Day 14.

CONCLUSIONS

DOX GITS significantly improved IPSS and Q(max) by Day 3 of treatment, and these changes were maintained through Day 14. More patients receiving DOX GITS than placebo perceived improvement in symptoms as early as Day 1.