What medications are used to treat urinary incontinence?

Medications for Urinary Incontinence

Treatment Approach Based on Incontinence Type

Pharmacologic therapy for urinary incontinence should be reserved for urgency incontinence after behavioral interventions fail, while medications are not recommended for stress incontinence. 1

Urgency (Urge) Incontinence

First-line pharmacologic agents are tolterodine or darifenacin due to their superior tolerability profiles, with discontinuation rates similar to placebo. 2

Antimuscarinic Medications (First-Line Pharmacologic Options)

• Tolterodine and darifenacin are preferred initial choices because they have the lowest discontinuation rates due to adverse effects, comparable to placebo 1, 2
• Solifenacin and fesoterodine demonstrate dose-response effects on symptom improvement and are effective alternatives 1
• Oxybutynin is effective but has the highest risk for discontinuation due to adverse effects (NNTH 16) and should be considered only after better-tolerated agents 1
• Trospium is another option with moderate tolerability 1

Efficacy and Limitations

• All antimuscarinic medications are equally efficacious at managing urgency incontinence, with moderate benefit in achieving continence rates 1, 2
• The absolute risk difference compared to placebo is less than 20% for all medications, indicating modest clinical benefit 1
• Pharmacologic therapy should only be initiated after bladder training has been unsuccessful 1, 2

Common Adverse Effects

• Dry mouth, constipation, blurred vision, and urinary retention are the most common anticholinergic side effects 1
• Oxybutynin causes the highest rate of dry mouth and insomnia compared to other agents 1
• Fesoterodine has more adverse effects than tolterodine, including dry mouth and headache (NNTH 11) 1
• Patient adherence is generally poor due to these adverse effects 1, 2

Beta-3 Adrenergic Agonists

• Mirabegron is an alternative with fewer anticholinergic side effects, though it causes nasopharyngitis and gastrointestinal disorders more frequently than placebo 1, 3

Stress Incontinence

Systemic pharmacologic therapy is not recommended for stress incontinence. 1, 2

• Standard pharmacologic therapies used for urgency incontinence have not been shown effective for stress incontinence 1
• Vaginal estrogen formulations may improve stress incontinence, but transdermal estrogen patches worsen it 1
• Alpha-adrenergic agonists (e.g., phenylpropanolamine) theoretically increase urethral sphincter tone but lack strong evidence 4, 5

Mixed Incontinence

• Pelvic floor muscle training combined with bladder training is recommended as first-line treatment 1
• If behavioral interventions fail, antimuscarinic medications may be considered for the urgency component 1

Medication Selection Algorithm

When selecting pharmacologic therapy for urgency incontinence, base the choice on tolerability, adverse effect profile, ease of use, and cost. 1, 2

1. Start with tolterodine or darifenacin due to favorable tolerability 2
2. Consider solifenacin if dose titration is needed, as it has the lowest discontinuation rate among agents with higher adverse effects (NNTH 78) 1
3. Avoid oxybutynin as initial therapy unless cost is prohibitive, given its high discontinuation rate 1
4. Consider mirabegron for patients who cannot tolerate anticholinergic effects 3

Critical Caveats

• Long-term safety data for incontinence medications are generally unavailable 1
• Age, race, baseline incontinence frequency, and obesity do not significantly modify treatment outcomes 1
• Patients taking 7 or more concomitant medications experience more adverse effects with trospium 1
• Dose reduction to 1 mg twice daily is recommended for tolterodine when used with CYP3A4 inhibitors (macrolide antibiotics, azole antifungals) or cyclosporine 6