Mirabegron for the Treatment of Pain Motivated Urinary Frequency and Urgency in Women

The specific purpose of this study is to provide objective data in prospective open label design (n=40) to support the use of Mirabegron as a treatment for pain related urinary frequency and urgency. Women with bladder pain have a poor response to traditional anticholinergic therapy for their symptoms of frequency and urgency.

Hypothesis: Mirabegron is effective in reducing symptoms in women with pain related urinary frequency and urgency.

Specific Aims:

1. To measure the efficacy of Mirabegron in the treatment of frequency and urgency, using voiding diaries.
2. To measure the number of patients with a 50% or greater reduction in frequency and urgency, using voiding diaries.
3. To measure the number of patients with a 50% or greater reduction in bladder pain as measured in the O'Leary-Sant (OLS) IC symptom and problem, and the Lowell Parsons Pelvic Pain and Urgency/Frequency (PUF) patient symptom scale.

Intervention/Project goal: Treatment with Mirabegron 25mg for 4 weeks with an option for dose escalation to 50mg. Duration of study 12 weeks.

Inclusion criteria: Women between the ages of 18 and 89 with complaints of pain related urinary frequency are eligible to participate in the study.

Exclusion criteria:

Patients will be excluded from the study if they have:

1. Severe Liver disease, Child-Pugh class c
2. Severe Kidney disease, GFR\<30
3. Elevated blood pressure \> 160/95 (in package insert bp \>180/110)
4. Urinary retention
5. Pregnant, will become pregnant, or are nursing
6. History of recurrent urinary tract infection
7. Tachycardia: pulse \> 100
8. Presently on study drug mirabegron; patient must be willing to participate in a 30 day washout period to be eligible for inclusion
9. Medications - metoprolol, desipramine, digoxin, propafenone, thioridazine, flecainide, warfarin

Eligibility Criteria:
Inclusion Criteria:

1. English-speaking women
2. Age: 18 and 89 years
3. Pain related urinary frequency or urgency associated with \>70% of voids. With a minimum of 7 pain motivated voids in 24 hours.
4. Bladder capacity: \> 300 ml
5. Urinary frequency: 10 or more voids in 24/hours on voiding diary

Exclusion Criteria:

1. Severe Liver disease: Child-Pugh class c
2. Severe Kidney disease: GFR\<30
3. Elevated blood pressure \> 160/95 (in package insert bp \>180/110)
4. Pregnant, will become pregnant, or are nursing during the study
5. History of recurrent urinary tract infection: 3 or more culture proven urinary tract infections in the past 12 months. An active urinary tract infection.
6. Tachycardia: pulse \> 100, or any other history of arrhythmia
7. Intense urge: bladder volumes of \<150 ml on cystometry
8. Presently on study drug mirabegron; patient must be willing to participate in a 30 day washout period to be eligible for inclusion
9. Medications: metoprolol, desipramine, digoxin, propafenone, thioridazine, flecainide, warfarin
10. Pain medications: no dose changes in narcotic or non-steroidal medications while on study. Patient must be on a stable medication dose for at least 30 days prior to the screening visit.
11. Neurogenic pain medications such as gabapentin or amitriptyline: no dose changes while on study. Patient must be on a stable medication dose for at least 30 days prior to the screening visit.
12. Anticholinergic medications for incontinence: no dose changes while on study. Patient must be on a stable medication dose for at least 30 days prior to the screening visit.