Burden and Efficacy of Anticholinergic vs Mirabegron in Overactive Bladder - A Randomized Controlled Study

NCT07711808 | Not Yet Recruiting Phase 4

• 1 other identifier: BEAM
• Study Type: interventional
• Target: 208
• Locations: 0 countries
• Sites: N/A

Brief Summary

Overactive bladder (OAB) is a common condition that causes a sudden, strong need to urinate, often with frequent daytime and night-time trips to the toilet, and sometimes leaking. It can have a substantial impact on everyday quality of life. Two of the most common medicines used to treat OAB work in different ways: one type (antimuscarinics, such as solifenacin) blocks a nerve signal in the bladder, while another type (beta-3 agonists, such as mirabegron) helps the bladder muscle relax. Many people with OAB are already taking other medicines - for example, for mood, sleep, or allergies - that, without being intended for the bladder, also block that same nerve signal. The combined effect of all these medicines is called the "anticholinergic burden." Researchers want to understand whether a person's existing anticholinergic burden changes how well each OAB treatment works. The idea is that if this nerve pathway is already heavily blocked by other medicines, an antimuscarinic might be less helpful, and a treatment that works in a different way (mirabegron) might be a better choice. In this study, adults with newly diagnosed OAB who have not yet been treated will be randomly assigned to take either solifenacin or mirabegron once a day. Before starting, each participant's anticholinergic burden will be measured using a validated tool called the Drug Burden Index (DBI) and ACB. Bladder symptoms will be assessed with a standard questionnaire (ICIQ-FLUTS) and a bladder diary at the start of treatment and again after 1 and 2 months. By comparing how participants respond depending on their baseline anticholinergic burden, the study aims to learn whether measuring this burden can help doctors choose the most effective first-line treatment for each patient.

Conditions

Overactive Bladder (OAB)

Keywords

Overactive bladder; Anticholinergic burden

Outcome Measures

Primary Outcomes (1)

• ICIQ OAB

  This measure captures how much overactive bladder symptoms change after two months of treatment. The ICIQ-OAB (International Consultation on Incontinence Questionnaire - Overactive Bladder) is a validated, patient-completed questionnaire covering the core symptoms of the condition: daytime urinary frequency, night-time urination (nocturia), urgency, and urgency-related leakage. The four symptom items are summed into a total score ranging from 0 to 16, where a higher score means more severe symptoms. Participants complete the questionnaire at the start of treatment (baseline) and again at 2 months; the outcome is the change between these two time points, with a larger reduction indicating greater symptom improvement. The two treatment arms are compared using an analysis of covariance (ANCOVA) adjusted for each participant's baseline score, performed separately within the high anticholinergic burden group (Drug Burden Index ≥ 1) and the low burden group (DBI \< 1).

  From enrollment to 4 and 8 weeks

Secondary Outcomes (4)

• Responder rate at Month 2

  From enrollment to 8 weeks

• Change in frequency-volume chart parameters at Month 2

  From enrollment to 8 weeks

• Treatment discontinuation rate

  From enrollment to the end of 8 weeks

• Incidence of adverse events

  From enrollment to the end of 8 weeks

Other Outcomes (1)

• Treatment-by-DBI-stratum interaction on ICIQ-OAB change at Month 2

  From enrollment to the end of 8 weeks

Study Arms (4)

Low Anticholinergic Burden - Solifenacin

EXPERIMENTAL

Participants randomized to this arm receive solifenacin succinate 5 mg, an oral selective M3 antimuscarinic, taken once daily for 2 months. Solifenacin reduces overactive bladder symptoms by blocking muscarinic receptor-mediated detrusor contractions.

Drug: Solifencin

Low Anticholinergic Burden - Mirabegron

ACTIVE COMPARATOR

Participants randomized to this arm receive mirabegron 50 mg, an oral β3-adrenergic agonist, taken once daily for 2 months. Mirabegron relieves overactive bladder symptoms through a non-anticholinergic mechanism, promoting detrusor relaxation during the storage phase.

Drug: Mirabegron

High Anticholinergic Burden - Mirabegron

ACTIVE COMPARATOR

Participants randomized to this arm receive mirabegron 50 mg, an oral β3-adrenergic agonist, taken once daily for 2 months. Mirabegron relieves overactive bladder symptoms through a non-anticholinergic mechanism, promoting detrusor relaxation during the storage phase.

Drug: Mirabegron

High Anticholinergic Burden - Solifenacin

EXPERIMENTAL

Participants randomized to this arm receive solifenacin succinate 5 mg, an oral selective M3 antimuscarinic, taken once daily for 2 months. Solifenacin reduces overactive bladder symptoms by blocking muscarinic receptor-mediated detrusor contractions.

Drug: Solifencin

Interventions

Solifencin DRUG

Patients will receive solifenacin succinate 5 mg, an oral selective M3 antimuscarinic, taken once daily for 2 months. Solifenacin reduces overactive bladder symptoms by blocking muscarinic receptor-mediated detrusor contractions.

High Anticholinergic Burden - Solifenacin; Low Anticholinergic Burden - Solifenacin

Mirabegron DRUG

Participants randomized to this arm receive mirabegron 50 mg, an oral β3-adrenergic agonist, taken once daily for 2 months. Mirabegron relieves overactive bladder symptoms through a non-anticholinergic mechanism, promoting detrusor relaxation during the storage phase.

High Anticholinergic Burden - Mirabegron; Low Anticholinergic Burden - Mirabegron

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult patients with a clinical diagnosis of overactive bladder syndrome.
• Treatment-naïve for OAB pharmacotherapy (no prior antimuscarinic or mirabegron for OAB).
• Able to complete the ICIQ-OAB questionnaire and a frequency-volume chart.
• Written informed consent.

You may not qualify if:

• Neurogenic bladder.
• Previous treatment with anticholinergics or mirabegron for OAB.
• History of pelvic radiotherapy or bladder cancer.
• Post-void residual volume \> 200 mL.
• Clinically significant stress urinary incontinence.
• Chronic pelvic pain syndrome.
• Congenital urinary tract malformations.
• Prior bladder surgery; history of mid-urethral sling or prostate surgery.
• Contraindication to solifenacin or mirabegron.
• End-stage renal disease on dialysis.

Sponsors & Collaborators

• Universidade do Porto: lead
• Unidade Local de Saúde São João: collaborator

MeSH Terms

Conditions

Urinary Bladder, Overactive

Interventions

mirabegron

Condition Hierarchy (Ancestors)

Urinary Bladder Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases; Lower Urinary Tract Symptoms; Urological Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 13, 2026
• First Posted: July 17, 2026
• Study Start: July 1, 2026
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): August 1, 2027
• Last Updated: July 17, 2026

Record last verified: 2026-06