A Twelve-Week Placebo-Controlled Study of Prazosin in the Treatment of Prostatic Obstruction

Abstract

Fifty-eight normotensive patients with benign prostatic hyperplasia and maximum urinary flow rates of less than 15 ml/s were randomly assigned to receive a 12-week course of treatment with prazosin or placebo in a double-blind parallel group trial. Prazosin was administered orally in doses of 0.5 mg and then 1 mg twice daily for 4 days each and 2 mg twice daily for the remainder of the trial. Patients on treatment with prazosin had an increased urinary flow rate as compared to placebo with a significant reduction in maximum voiding detrusor pressure and maximum detrusor pressure at peak urinary flow. Although a significant effect on frequency was not demonstrated, standard parameters of detrusor instability were reduced. Investigators’ double-blind overall assessment of efficacy significantly favoured the prazosin treatment. Twelve patients were excluded from the final analysis, 8 being withdrawn because of adverse effects, 5 on treatment with prazosin and 3 in the placebo group. Oral prazosin appears to be safe and effective in the long-term treatment of patients with benign prostatic hyperplasia.

A dose‐ranging study of the efficacy and safety of tamsulosin, the first prostate‐selective &agr;1A‐adrenoceptor antagonist*, in patients with benign prostatic obstruction

“…These changes in Q max are similar to those reported recently for tamsulosin 0.4 mg three tamsulosin groups. There were no apparent dosedependent clinically significant eÂects of tamsulosin on in Phase III studies in Europe (1.6 versus 0.6 mL/s in the placebo group) [30] and in the USA (1.8 versus any of the laboratory variables measured. 0.5 mL/s in the placebo group) [31].…”

“…was asthenia in three patients (one on placebo and two and urinary flow in subsequent European phase III studies [29,30] and in one phase III study in the USA on 0.6 mg tamsulosin). Serious adverse events were reported for three patients, and included epistaxis (pla-…”

“…Patients with LUTS suggestive of BPO find their urinary ments compared to placebo at 4 weeks [29,30]. For Q max , the eÂect was also maximal after 4 weeks [29,30] symptoms bothersome and relief of these symptoms is one of the primary goals of therapy with a 1 -adrenoceptor and was maintained for up to 60 weeks [32].…”

“…For Q max , the eÂect was also maximal after 4 weeks [29,30] symptoms bothersome and relief of these symptoms is one of the primary goals of therapy with a 1 -adrenoceptor and was maintained for up to 60 weeks [32]. Maximal improvements in mean total Boyarsky symptom scores antagonists.…”

“…Maximal improvements in mean total Boyarsky symptom scores antagonists. Many clinical studies have used the Boyarsky scale [38] or a modified version of it, such as were seen after 12-14 weeks of tamsulosin therapy [29,30,32] and maintained thereafter [32]. The phase that used in the present study to evaluate urinary symptoms.…”