What medications are effective for treating overactive bladder (OAB) and urinary urgency?

Medications for Overactive Bladder and Urinary Urgency

For overactive bladder (OAB) and urinary urgency, first-line treatment should be behavioral therapies, followed by oral antimuscarinic medications or beta-3 adrenergic agonists as second-line therapy, with combination therapy reserved for refractory cases.

Treatment Algorithm

First-Line Treatment: Behavioral Therapies

• Behavioral therapies should be offered as first-line treatment to all patients with OAB symptoms 1
• These include:
  • Bladder training and delayed voiding 1
  • Pelvic floor muscle training and urge suppression techniques 1
  • Fluid management (25% reduction in fluid intake can reduce frequency and urgency) 1
  • Weight loss for obese patients (8% weight loss can reduce urgency urinary incontinence episodes by 42%) 1
  • Caffeine reduction 1

Second-Line Treatment: Pharmacologic Options

Antimuscarinic Medications

• Oral antimuscarinics are standard second-line therapy when behavioral approaches are insufficient 1
• Options include (alphabetically, no hierarchy implied):
  • Darifenacin 1
  • Fesoterodine 1
  • Oxybutynin (available in oral and transdermal formulations) 1, 2
  • Solifenacin 1
  • Tolterodine 1, 3
  • Trospium 1, 4

Beta-3 Adrenergic Agonists

• Mirabegron is indicated for OAB in adults with symptoms of urge urinary incontinence, urgency, and frequency 5
• Starting dose is 25 mg once daily, which may be increased to 50 mg once daily after 4-8 weeks if needed 5

Considerations for Medication Selection

Antimuscarinic Side Effects and Contraindications

• Common side effects include dry mouth, constipation, dry eyes, blurred vision, dyspepsia, UTI, and urinary retention 1
• Contraindicated in patients with:
  • Narrow-angle glaucoma (unless approved by ophthalmologist) 1
  • Impaired gastric emptying or history of urinary retention (use with extreme caution) 1
  • Patients using solid oral forms of potassium chloride 1
• Transdermal oxybutynin (TDS) may be offered if dry mouth is a concern with oral antimuscarinics 1, 2

Special Populations

• Elderly patients:
  • Higher risk of cognitive adverse events with certain antimuscarinics 4
  • Consider medications with lower CNS penetration 4
• Renal impairment:
  • For mirabegron, adjust dosing based on estimated GFR 5
  • Not recommended for eGFR <15 mL/min/1.73m² 5
• Hepatic impairment:
  • For mirabegron, maximum dose is 25 mg for moderate hepatic impairment 5
  • Not recommended for severe hepatic impairment 5

Combination Therapy for Refractory Cases

• Behavioral therapies may be combined with antimuscarinic therapies 1
• For patients refractory to monotherapy, combination of an antimuscarinic and β3-adrenoceptor agonist (e.g., solifenacin plus mirabegron) may be considered 1
• Combination therapy has shown improved efficacy over monotherapy in reducing:
  • Urinary incontinence episodes 1
  • Urgency episodes 1
  • Nocturia 1
  • Micturitions per 24 hours 1

Third-Line Treatments

• For patients who fail behavioral and medical therapy:
  • Neuromodulation or onabotulinumtoxinA therapy may be offered 1
  • Evaluation by an appropriate specialist is recommended 1

Important Clinical Considerations

• Most patients will not experience complete symptom relief but can expect significant reductions in symptoms and improvements in quality of life 1
• Patients with more severe symptoms typically experience greater symptom reductions 1
• Post-void residual (PVR) assessment may be useful in patients suspected of higher risk of urinary retention before starting antimuscarinic therapy 1
• Regular monitoring of blood pressure is important, especially with mirabegron 5
• Treatment should be tailored based on the patient's symptom severity, comorbidities, and potential for adverse effects 1