Mirabegron as a Medical Expulsive Therapy for 5-10 mm Distal Ureteral Stones: A Prospective, Randomized, Comparative Study

In vitro effects of β3-adrenoceptor agonist mirabegron on the human ureter

INTRODUCTION

This study aimed to investigate the effect of mirabegron, a β3-adrenoceptor agonist with widespread clinical use for treating overactive bladder disease, on isolated healthy human ureter strips.

MATERIALS AND METHODS

This was a prospective study employing a series of in vitro organ bath experiments using ureteral tissues of kidney grafts from 10 healthy donors. The ureteral strips were subjected to cumulative mirabegron concentrations (10-9-10-4.5 M). Effects on frequency or amplitude of spontaneous, 10 mM KCl- or EFS-induced contractions were evaluated.

RESULTS

Mirabegron decreased the frequency of spontaneous ureteric contraction in a concentration-dependent manner. Statistically significant decrease in the frequency of spontaneous contraction was observed at 10-8-10-4.5 M. In 10 mM KCl medium, statistically significant change in frequency was observed at 10-9-10-4.5 M. Statistically significant decrease in the amplitudes of spontaneous contraction was observed at 10-7-10-4.5 M. In a 10 mM KCl medium, statistically significant change in amplitudes was observed at 10-8-10-4.5 M.

CONCLUSIONS

Mirabegron reduced the amplitude and frequency of human ureter activity in in vitro organ bath studies. This effect was achieved in a dose-dependent manner on isolated tissue strips. Although monotherapy with mirabegron remains uncertain, this study has the potential to elucidate the mechanism underlying the effectiveness of mirabegron, particularly in combination therapy for ureteral stones.

Mirabegron for medical expulsive therapy of ureteral stones: a systematic review and meta-analysis

Objective

To systematically review and quantitively evaluate the efficacy and safety of mirabegron as a medical expulsive therapy for ureteral stones.

Methods

We performed an extensive search of the EMBASE and PubMed databases for studies examining the use of mirabegron as a medical expulsive therapy for ureteral stones. The primary outcome measure assessed was the stone expulsion rate (SER), while the secondary outcomes evaluated were the stone expulsion interval (SEI) and the occurrence of pain episodes during follow-up. Risk ratios (RRs) and mean differences (MDs) with their respective 95% CIs were calculated.

Results

We included a total of seven studies involving 728 participants. Our analysis revealed a significant increase in the stone expulsion rate (SER) with mirabegron (RR = 1.40; 95% CI = 1.17-1.67; p < 0.001) and a reduction in the frequency of pain episodes (MD = -0.80; 95% CI = -0.39 to -0.21; p = 0.008) compared to the control group. No significant difference was found in SEI between the two groups (MD = -3.04; 95% CI = -6.33 to 0.25; p = 0.07). Subgroup analysis revealed that the increased SER was significant for distal ureteral stones, but not for proximal and middle ureter stones. Compared to tamsulosin or silodosin, mirabegron showed no significant difference in SER, SEI, or pain episode frequency. The adverse effects of mirabegron were relatively rare and mild.

Conclusion

Mirabegron appears to be a promising candidate for the MET of distal ureteral stones rather than proximal and middle ureteral stones, as it significantly increases SER and reduces pain episode frequency. Further well-designed randomised controlled trials are needed to validate and affirm these findings.

Systematic Review Registration

PROSPERO (CRD42022341603).

Efficacy of mirabegron for ureteral stones: a systematic review with meta-analysis of randomized controlled trials

Background: Medical expulsive therapy demonstrates efficacy in managing ureteral stones in patients amenable to conservative interventions. This meta-analysis aims to evaluate the effectiveness of mirabegron in the treatment of ureteral stones. Methods: From conception to November 2023, we examined PubMed databases, the Cochrane Library, Embase, Ovid, Scopus, and trial registries for this systematic review and meta-analysis. We chose relevant randomized controlled trials (RCTs) evaluating the efficacy of mirabegron as an expulsive treatment for ureteral stones. The Cochrane risk of bias method was used to assess the quality of the evidence. Outcome measures, which included the stone expulsion rate (SER), expulsion time, and pain episodes, were analyzed using RevMan 5.4 and Stata 17. Results: Seven RCTs (N = 701) had enough information and were ultimately included. In patients with ureteral stones, mirabegron-treated patients had a substantially higher SER [odds ratio (OR) = 2.57, 95% confidence interval (CI) = 1.41-4.68, p = 0.002] than placebo-treated patients. Subgroup analysis revealed that mirabegron was superior to placebo in patients with small ureteral stones (OR = 2.26, 95% CI = 1.05-4.87, p = 0.04), with no heterogeneity between studies (p = 0.54; I2 = 0%). Mirabegron patients had a higher SER than the control group for distal ureteral stones (DUSs) (OR = 2.48, 95% CI = 1.31-4.68, p = 0.005). However, there was no difference in stone ejection time or pain episodes between groups. Conclusion: Mirabegron considerably improves SER in patients with ureteral stones, and the effect appears to be more pronounced for small and DUSs. Nevertheless, mirabegron treatment was not associated with improved stone expulsion time or pain management.