What medications are used to treat urge incontinence?

Medications for Urge Incontinence

Mirabegron is recommended as a first-choice pharmacologic therapy for urge incontinence due to its superior side effect profile and comparable efficacy to antimuscarinic medications. 1

First-Line Pharmacologic Options

Beta-3 Adrenergic Agonists

• Mirabegron (Myrbetriq)
  • Starting dose: 25 mg once daily 2
  • May increase to 50 mg once daily after 4-8 weeks if needed 2
  • Indicated for overactive bladder with symptoms of urge urinary incontinence 2
  • Advantages: Better side effect profile than antimuscarinics 1
  • Common side effects: Hypertension, nasopharyngitis, UTI, headache 2
  • Monitoring: Regular blood pressure checks, especially in hypertensive patients 2

Antimuscarinic Medications

• Solifenacin

  • Lowest risk for discontinuation due to adverse effects among antimuscarinics 1
  • Number needed to benefit (NNTB) of 9 for achieving continence 1
  • Better tolerated than immediate-release oxybutynin 1

• Tolterodine

  • Indicated for overactive bladder with symptoms of urge urinary incontinence 3
  • Reduces micturition frequency by 22% and urge incontinence episodes by 71-76% 1
  • Better tolerated than oxybutynin with lower discontinuation rates 1
  • Standard dose: 2 mg twice daily 1

• Fesoterodine

  • More effective than tolterodine but with higher risk of dry mouth 1

Comparative Efficacy and Tolerability

Mirabegron vs. Antimuscarinics

• Mirabegron shows comparable efficacy to antimuscarinics with fewer side effects 1
• The American College of Physicians and American Urological Association recommend mirabegron as a first-choice therapy 1

Among Antimuscarinics

• Solifenacin vs. Tolterodine:

  • Solifenacin shows better efficacy for quality of life, patient-reported cure/improvement, and reduction in leakage episodes 4
  • Lower risk of dry mouth with solifenacin compared to immediate-release tolterodine 4

• Fesoterodine vs. Extended-Release Tolterodine:

  • Fesoterodine demonstrates superior efficacy for quality of life, patient-reported cure/improvement, and reduction in leakage episodes 4
  • Higher risk of withdrawal due to adverse events and dry mouth with fesoterodine 4

• Tolterodine vs. Oxybutynin:

  • Similar efficacy but significantly fewer side effects with tolterodine 5
  • 52% lower risk of withdrawals due to adverse events with tolterodine 4
  • 35% lower risk of dry mouth with tolterodine 4

Common Side Effects of Antimuscarinic Medications

• Oxybutynin: Highest incidence of dry mouth (71.4%), constipation (15.1%), blurred vision (9.6%), dizziness (16.6%), somnolence (14%) 1
• Fesoterodine: Higher rates of adverse effects than tolterodine 1
• Tolterodine: Better side effect profile than oxybutynin 1
• Trospium: Lower incidence of constipation compared to other antimuscarinics 1
• Darifenacin: Risk for discontinuation due to adverse effects similar to placebo 1
• Solifenacin: Lowest risk for discontinuation due to adverse effects 1

Clinical Pearls and Pitfalls

• Allow 4-8 weeks for medications to determine efficacy before considering dose adjustments or switching medications 1
• Extended-release formulations generally have fewer side effects than immediate-release preparations 4
• Consider starting with lower doses in elderly patients or those with hepatic/renal impairment 2
• Monitor blood pressure regularly in patients taking mirabegron, especially those with hypertension 2
• Use caution in patients with bladder outlet obstruction due to risk of urinary retention 2
• Consider combination therapy with α-blockers and antimuscarinics for men with both storage and voiding symptoms 1

Treatment Algorithm

1. First-line: Mirabegron 25 mg daily (increase to 50 mg after 4-8 weeks if needed)
2. Alternative first-line: Solifenacin or tolterodine if mirabegron is contraindicated or not tolerated
3. Second-line: Switch to a different antimuscarinic or consider combination therapy
4. Third-line: Consider advanced options (sacral neuromodulation, peripheral tibial nerve stimulation, or onabotulinumtoxinA injections) for refractory cases 1