Doxazosin in the Treatment of Benign Prostatic Hyperplasia in Normotensive Patients

Abstract

A 16-week, double-blind, placebo controlled, dose titration study was done on 100 normotensive patients age 45 years or older to determine the efficacy and safety of doxazosin, a selective alpha 1-adrenoceptor antagonist, in the treatment of benign prostatic hyperplasia (BPH). Of the 41 efficacy evaluable patients 88% underwent dose titration to a maximum of 8 mg. doxazosin once daily. Maximum and average urinary flow rates increased significantly above baseline with doxazosin (2.9 ml. per second and 1.4 ml. per second, respectively) compared with placebo (0.7 ml. per second and 0.3 ml. per second, respectively). A significant effect on maximum flow rate was noted as early as week 2 of double-blind treatment at the initial efficacy evaluation. Doxazosin was superior to placebo in patient and investigator assessments of total, obstructive and irritative BPH symptoms. The onset of efficacy for total patient-assessed symptoms was significant for doxazosin compared to placebo 4 weeks after the start of the treatment regimen. Statistically significant decreases in mean blood pressure of 4 to 6 mm. Hg were noted with doxazosin compared with placebo. Adverse events, primarily mild to moderate in severity, were reported in 44% of patients given doxazosin and 30% of those given placebo. Our results strongly demonstrate that doxazosin is significantly superior to placebo in the treatment of BPH in normotensive patients, with the patient experiencing significant relief early after initiation of therapy.

Clinical Uroselectivity of Alfuzosin in the Treatment of Benign Prostatic Hyperplasia

“…Postural hypotension was shown to be four times more frequent in patients who received terazosin than in those who received placebo or finasteride; dizziness was three times more frequent and asthenia twice as frequent (table 1). As far as dizziness, hypotension and asthenia are concerned, doxazosin has a similar adverse event profile as terazosin, as indicated in two placebo-controlled studies (table 2) [26, 27], where similar figures were observed.…”

Clinical Experience in Europe with Uroselective α₁-Antagonists

“…The International Doxazosin Study in which many European centres participated confirmed the superiority and relative safety of the drug over placebo [25, 26]. However the (cardiovascular) side-effects were comparable with terazosin and therefore like for terazosin initial titration is advised.…”

Tamsulosin: Real Life Clinical Experience in 19,365 Patients

“…doxazosin and terazosin) have reported that their blood pressure-lowering effects may be enhanced in patients with concomitant antihypertensive treatment [15, 16, 17, 18, 19]. In normotensive patients with LUTS suggestive of BPO, these drugs can also cause blood pressure reductions which are small but significantly greater than with placebo [19, 20, 21]. In contrast, the blood pressure effects of tamsulosin were similar to those of placebo in controlled studies, both in normotensive and in hypertensive patients [10].…”