Medications for Urinary Incontinence
For urgency incontinence (overactive bladder), use antimuscarinic medications or beta-3 agonists as first-line pharmacotherapy only after behavioral therapy fails; for stress incontinence, do not use systemic pharmacologic therapy at all. 1, 2
Treatment Algorithm by Incontinence Type
Urgency Urinary Incontinence (Overactive Bladder)
Step 1: Non-pharmacologic therapy first
- Start with bladder training (strong recommendation, moderate-quality evidence) 1
- Pharmacotherapy should only be initiated if bladder training is unsuccessful 1
Step 2: Pharmacologic options when behavioral therapy fails
When selecting medications, base your choice on tolerability and adverse effect profile rather than efficacy, since all agents are equally effective 1. The key differentiator is side effects:
Preferred agents (lowest discontinuation rates):
- Darifenacin - discontinuation rate similar to placebo 1
- Tolterodine - discontinuation rate similar to placebo 1
- Solifenacin - lowest risk for discontinuation among all agents (NNTH: 78) 1
Moderate tolerability:
- Mirabegron (beta-3 agonist) - associated with nasopharyngitis and GI disorders rather than anticholinergic effects 1
- Fesoterodine - higher discontinuation than tolterodine (NNTH: 33) 1
- Trospium - moderate discontinuation rate (NNTH: 56) 1
Avoid as first choice:
- Oxybutynin - highest discontinuation rate due to adverse effects (NNTH: 16), most dry mouth, constipation, blurred vision 1
Critical Safety Considerations for Antimuscarinics
Dementia risk: Discuss the association between antimuscarinic medications and incident dementia with all patients, which may be cumulative and dose-dependent. Prefer beta-3 agonists (mirabegron) before antimuscarinics when possible 2.
Absolute caution/contraindications:
- Narrow-angle glaucoma
- Impaired gastric emptying
- History of urinary retention
- Additional caution: diabetes, prior abdominal surgery, narcotic use, scleroderma, hypothyroidism, Parkinson's disease, multiple sclerosis 2
Stress Urinary Incontinence
Do not prescribe systemic pharmacologic therapy for stress incontinence (strong recommendation, low-quality evidence) 1.
- Standard pharmacologic therapies used for urgency incontinence have not been shown effective for stress incontinence 1
- Pelvic floor muscle training is first-line treatment 1, 3
- Vaginal estrogen formulations may improve stress incontinence, but transdermal estrogen patches worsen it 1
Mixed Urinary Incontinence
- Start with pelvic floor muscle training combined with bladder training 1
- If behavioral therapy fails and urgency component predominates, use the pharmacologic approach outlined above for urgency incontinence
Common Adverse Effects Profile
Antimuscarinics: Dry mouth (most common), constipation, blurred vision, potential cognitive impairment 1, 2
Beta-3 agonists (mirabegron): Nasopharyngitis, gastrointestinal disorders - notably no anticholinergic effects 1
Key Clinical Pitfalls
Never use systemic medications for isolated stress incontinence - they don't work and expose patients to unnecessary side effects 1
Don't skip behavioral therapy - jumping straight to medications ignores effective, low-risk interventions with large magnitude of benefit 1
Monitor for discontinuation - many patients stop medications due to adverse effects; if no improvement is noted after adequate trial, discontinue rather than continuing ineffective therapy 2
Screen for reversible causes - UTI, metabolic disorders, excess fluid intake, delirium, and medications that worsen incontinence before starting treatment 1
Consider cognitive risks in all ages - the dementia association with antimuscarinics isn't limited to elderly patients 2