Doxazosin for benign prostatic hyperplasia: Long-term efficacy and safety in hypertensive and normotensive patients

Purpose: We evaluated the sustained efficacy and safety of doxazosin for long-term treatment (up to 48 months) of normotensive and hypertensive patients with benign prostatic hyperplasia (BPH). Materials and Methods: A total of 272 normotensive and 178 mildly to moderately hypertensive men entered a long-term extension study of doxazosin therapy (1 to 8 and 1 to 12 mg. 1 time daily, respectively) for BPH following participation in double-blind, placebo controlled studies. The starting dose of doxazosin was 1 mg. with upward titrations at 2-week intervals to a stable, efficacious and well tolerated dose. At the time of data analysis patients had received between 1 and 48 months of stable dose doxazosin therapy (mean 668 days for normotensive and 807 for hypertensive patients). Mean daily doses were 4 and 6.4 mg. for normotensive and hypertensive men, respectively. Results: At the end point analysis doxazosin treatment resulted in significant increases above baseline in maximum and average urinary flow rates (1.9 and 1.0 mi. per second, respectively). As assessed by the patient, total, obstructive and irritative BPH symptoms also improved significantly with doxazosin treatment. In the 28 patients who completed 45 to 48 months of treatment improvement in symptom bothersomeness (13.2%) was similar to that of the overall group at the end point (14.8%). Sustained blood pressure decreases (approximately 8/11 mm. Hg systolic/diastolic blood pressure) with doxazosin were statistically and clinically significant in hypertensive patients. Blood pressure decreases in normotensive patients were not clinically significant (approximately 4/2 mm. Hg) and few withdrew from study for reasons related directly to decreased blood pressure or hypotension. Changes in heart rate were not significant. Doxazosin was well tolerated with almost 90% of adverse experiences considered mild or moderate in severity. The most common adverse events were dizziness, headache and fatigue in normotensive and hypertensive patients. Conclusions: In this study long-term doxazosin treatment was significantly effective and well tolerated for treating BPH in normotensive and hypertensive patients.