Isosorbide dinitrate as an effective adjunct therapy for acute urinary retention: A randomized controlled trial

To evaluate the synergistic effect and safety of sublingual isosorbide dinitrate (ISDN) to facilitate successful voiding trial after catheterization for acute urinary retention (AUR) secondary to benign prostatic hyperplasia (BPH).

In this randomized clinical trial, male patients aged ≥ 50 years presenting with first-episode AUR secondary to BPH at our urology emergency department were enrolled during 2019-2020. Participants were randomly assigned to receive either standard therapy (α1-blocker and 5α-reductase inhibitor) alone (n = 40) or in combination with daily sublingual ISDN 10 mg for 21 days (n = 40). Primary outcomes included successful voiding post-catheter removal as trial without catheter (TWOC) and post-void residual (PVR) volume. Secondary outcomes included post-treatment prostate-specific antigen (PSA) levels and adverse events. Data were analysed using independent t-tests and chi-square tests.

A total of 80 men with similar baseline characteristics were enrolled (mean ages: 70.3 ± 7.97 in the ISDN group vs. 68.2 ± 8.73 years in the controls). The rate of successful TWOC was significantly higher in the ISDN plus standard therapy group compared with standard therapy alone (50.0% vs. 22.5%, p = 0.011). PVR volume decreased significantly after treatment in both groups (within-group p < 0.001), with a greater overall reduction observed in the ISDN group (p = 0.002). PSA levels remained stable, with no significant within- or between-group differences. On multivariable logistic regression analysis, adjunctive ISDN therapy independently predicted successful TWOC (adjusted OR 3.27, 95% CI 1.23-8.70; p = 0.017). No serious adverse events were observed.

Adjunctive sublingual ISDN significantly improves urinary outcomes following AUR and reduces residual urine volume without increasing adverse events. This combination therapy offers a safe and effective strategy to improve the success of TWOC in patients with BPH-related AUR.