The Effect of Oral Tamsulosin vs. Oral Tamsulosin and Oral Isosorbide Dinitrate in Acute Urinary Retention Patients Due to Benign Prostatic Hyperplasia: A Double-Blind Clinical Trial Study

Acute urinary retention due to benign prostatic enlargement is one of the clinical complaints that patients refer to the emergency department. Selective α-blockers are used after urinary catheterization. Recently, the use of nitrate compounds has been shown to relieve bladder neck and to treat acute urinary retention. 

The aim of this study was to survey the addition of Isosorbide di nitrate to tamsulosin in the treatment of acute urinary retention in patients with benign prostatic hyperplasia. 

This is a randomized, double-blind placebo-controlled clinical trial. In all, 78 patients with benign prostatic hyperplasia-related acute urinary retention referred to the emergency department were divided into two groups and randomly assigned to receive either 0.4 mg tamsulosin plus placebo or 0.4 mg tamsulosin plus isosorbide dinitrate 40 mg extended-release tablets daily for 3 days. At the same first visit, the catheter was removed and the ability to void in same time and 1 month later was assessed in each group. 

After catheter removal, 27 (67.5%) patients in the tamsulosin plus placebo group and 31 (81.6%) in the tamsulosin plus isosorbide dinitrate group voided successfully after 3 days (p = 0.155). After 1 month, 20 (50.0%) patients taking tamsulosin plus placebo and 23 (60.5%) taking tamsulosin plus isosorbide dinitrate could void, yet indicating no significant difference (p = 0.350). 

Addition of isosorbide dinitrate to α-blockers has advantage in improving benign prostatic hyperplasia-related acute urinary retention versus tamsulosin alone, although was not statistically significant.