Mirabegron as Medical Expulsive Therapy (MET) for Ureteral Stones and Ureteral Stent Pain

The study will be a prospective randomized double-blind placebo-controlled trial of
mirabegron for medical expulsive therapy (MET) in patients with a CT scan-proven ureteral
stone between 4 to 10 mm undergoing expectant management. Subjects will be distributed at a
1:1 ratio between the control and treatment groups. The treatment group will receive
mirabegron and the control groups will receive a placebo. Both groups will receive analgesics
and hydration will be recommended. All subjects will then be followed for 30 days to
determine the proportion of subjects with spontaneous passage. Patients will record narcotic
usage and pain scores during this time. If there is stone persistence in the ureter based on
imaging (CT scan of the abdomen and pelvis versus renal ultrasound plus KUB), then the
patient will undergo ureteroscopy with stent placement. In these patients, treatment will
continue while the stent is in place and patients will fill out a validated questionnaire
regarding stent pain.

Inclusion Criteria:

- Single unilateral ureteral calculus 4 to 10 mm visible on CT scan within the ureter

- Serum creatinine within normal range

- Ability to tolerate oral fluids and oral pain medication

- Able to make informed medical decisions regarding consent

- Willingness to follow-up in the Urology Clinic in approximately 30 day

- Willing to undergo ureteroscopic extraction should the stone not pass in this time
period

Exclusion Criteria:

- Adults unable to consent

- Age less than 18

- Multiple stones

- Solitary kidney

- Horseshoe kidney

- On immunosuppressant therapy

- On digoxin

- Uncontrolled hypertension (Systolic blood pressure > 170, diastolic blood pressure >
110)

- History of ureteral surgery or previous endoscopic procedure

- Allergy to mirabegron

- Current calcium antagonist or corticosteroid or tamsulosin usage

- Patients already taking a beta-adrenergic agonist medication

- Renal insufficiency [Glomerular Filtration Rate (GFR) less than 60]

- Patients with Childs B and C liver failure

- Signs of infection i. Temperature greater than 38 degrees Celsius ii. Urinalysis with
any of the following positive:

1. Positive nitrites

2. White blood cell count greater than 15/hpf (high powered field)

3. Positive urine culture [defined as a single isolated bacterial species population
of greater than 100,000 Colony Forming Units (CFU)]

- Patients with chronic pain already undergoing treatment with narcotic medications

- Pregnant women and nursing mothers

- Prisoners

- No working phone number