What medication and dosage is recommended for an 83-year-old woman with urinary incontinence (inability to control urination)?

Medication Treatment for Urinary Incontinence in an 83-Year-Old Woman

For an 83-year-old woman with urinary incontinence, mirabegron (Myrbetriq) at a starting dose of 25 mg once daily is recommended as first-line pharmacological therapy, with potential to increase to 50 mg daily if needed after 4-8 weeks. 1

Assessment of Incontinence Type

Before starting medication, it's crucial to determine the type of incontinence:

• Urge incontinence: Sudden, intense urge to urinate followed by involuntary leakage
• Stress incontinence: Leakage with physical activity, coughing, sneezing
• Mixed incontinence: Combination of both urge and stress symptoms
• Overflow incontinence: Constant dribbling due to bladder not emptying properly

In elderly women, urge incontinence is most common, followed by mixed incontinence 2.

Treatment Algorithm

First-Line: Non-Pharmacological Approaches

1. Pelvic floor muscle training (PFMT): Supervised program of repeated voluntary pelvic floor muscle contractions 2, 1
2. Bladder training: Scheduled voiding with gradually extending time between voids 1
3. Fluid management: 25% reduction in fluid intake if appropriate 1
4. Weight loss: If patient is obese 2, 1

Second-Line: Pharmacological Treatment

For urge or mixed incontinence with predominant urge component:

1. First choice: Mirabegron (β3-adrenoreceptor agonist)

   • Starting dose: 25 mg once daily
   • May increase to 50 mg once daily after 4-8 weeks if needed
   • Advantages: Better side effect profile than antimuscarinics, especially in elderly 2, 1
   • Evidence shows improvement in UI with NNT of 9 2, 1

2. Alternative options (if mirabegron contraindicated or ineffective):

   • Solifenacin: 5 mg once daily, may increase to 10 mg if needed

     • Better tolerated than immediate-release oxybutynin 1, 3
     • Lower discontinuation rates due to adverse effects 2, 3

   • Tolterodine: 2 mg twice daily or 4 mg extended-release once daily

     • Better side effect profile than oxybutynin 1, 4
     • Appropriate for elderly due to fewer CNS effects 4

   • Trospium: 20 mg twice daily

     • Lower incidence of constipation compared to other antimuscarinics 2, 1
     • Less likely to cross blood-brain barrier (advantage in elderly) 1

For stress incontinence:

• Vaginal estrogen: Consider for postmenopausal women with NNTB of 5 1

Special Considerations for Elderly Patients

1. Reduced dosing: Start with lowest effective dose and titrate slowly

   • For solifenacin: Start with 5 mg daily 3
   • For tolterodine: Consider 1 mg twice daily if hepatic/renal impairment 4

2. Avoid in elderly patients:

   • Immediate-release oxybutynin due to high incidence of CNS effects (71.4% dry mouth, 16.6% dizziness) 1, 5
   • Anticholinergics if patient has dementia, narrow-angle glaucoma, or significant bladder outflow obstruction 4, 5

3. Monitor for:

   • CNS effects: confusion, agitation, somnolence 4, 5
   • Urinary retention, especially if history of bladder outflow obstruction 4, 5
   • Constipation and other anticholinergic side effects 2, 1

Efficacy Expectations

• Medications typically reduce incontinence episodes by 1-2 per day 2, 3
• Allow 4-8 weeks to determine efficacy 1
• Approximately 30% of elderly women report being cured of incontinence with appropriate treatment, and another 30% report significant improvement 6

Follow-up and Monitoring

• Assess response after 4-8 weeks 1
• If inadequate response, consider:
  1. Increasing dose if tolerated
  2. Switching to alternative medication
  3. Referral for specialist evaluation if no improvement with multiple interventions

Cautions

• Antimuscarinic medications (solifenacin, tolterodine, oxybutynin) should be used with caution in elderly patients due to increased risk of cognitive side effects 4, 5
• Polypharmacy is common in elderly patients; review all medications for potential interactions 2
• Fluoroquinolones should be avoided for UTI prophylaxis in elderly patients with incontinence 2

Remember that urinary incontinence is never a normal part of aging and can be effectively treated even in very elderly patients 6, 7.