Efficacy of Mirabegron as Medical Expulsive Therapy for Distal Ureteral Stones: A Prospective, Randomized, Double-Blinded, Controlled Study

Abstract

Background: Today, medical expulsive therapy (MET) is more effective and commonly used in distal ureteral stones when compared with conservative treatments. Many treatments, namely, alpha-adrenergic blockers and calcium channel blockers, prostaglandin synthesis inhibitors, glyceryl trinitrate, and steroids, have been, therefore, utilized to mitigate such complications and accelerate stone expulsion. Several animal and human studies revealed the presence of β3-receptors in the ureter and bladder, where stimulating these receptors could relax the distal ureteral segment. Objectives: The aim of the study was to evaluate the efficacy of use of mirabegron as MET for distal ureteral stones (intramural and extramural). Methods: This is a prospective randomized controlled study including 90 patients who had distal ureteral stones less than 10 mm and were evaluated between January and June 2020. The patients were classified into 3 groups: group (A) 30 patients: mirabegron 50 mg d−1 + diclofenac Na 100 mg tab (to be taken only during colic episodes), group (B) 30 patients: tamsulosin HCL 0.4 mg cap + diclofenac Na 100 mg tab (to be taken only during colic episodes), and group (C) 30 patients: diclofenac Na 100 mg tab only (to be taken only during colic episodes). Age, sex, stone size, laterality, and grade of ureterohydronephrosis were recorded. Patients were observed for 30 days, and ureteroscopy was completed for those with nonexpulsed stones. Follow-up parameters included number of renal colic episodes, duration of medical therapy, stone expulsion time, and stone expulsion rate (SER). Results: In the group (A), 2 (6.6%) patients were excluded due to nasal congestion, and 1 (3.3%) patient was excluded due to a 20-mm Hg systolic blood pressure increase. Four (13.3%) patients in group (B) were noncompliant on medical treatment. In addition, 2 (6.6%) patients in group (A), 1 (3.3%) patient in group (B), and 5 (16.6%) patients in group (C) who did not attend follow-up examinations were excluded from the study. The SER increased significantly in group (A) and (B) when compared with group (C). The mean time of stone expulsion was about 15, 25, and 12 days for groups A, B, and C, respectively, and there was a significant statistical difference (p value = 0.006) among the 3 groups. The mean number of renal colic episodes of group (A) of patients was 1.8 times, while that of group (B) was 2.6 times and that of group (C) was 2.16 times with no significant statistical difference after comparing the 3 groups (p value = 0.660). Conclusions: Treatment with mirabegron appears to be a safe and effective medical expulsion therapy for distal ureteric stones and is better than tamsulosin.