Urge Urinary Incontinence (Urgency Incontinence)
The clinical presentation of urinary leakage that is NOT triggered by increased intra-abdominal pressure indicates urge urinary incontinence (UUI), which is involuntary leakage accompanied by or immediately preceded by a sudden, compelling desire to void that cannot be deferred. 1, 2
Distinguishing Features from Stress Incontinence
Urge incontinence is characterized by leakage accompanied by urgency, independent of physical activity or increased abdominal pressure, whereas stress urinary incontinence occurs specifically during coughing, sneezing, lifting, or exertion 3, 2
The underlying mechanism involves detrusor overactivity—involuntary bladder contractions during filling—rather than urethral sphincter failure 1, 4
Patients typically report urgency, frequency (>8 voids per 24 hours), nocturia, and leakage episodes that occur with sudden urge rather than during physical activities 3, 1
Diagnostic Evaluation
Obtain a 3-day voiding diary documenting urgency episodes, incontinence frequency, voided volumes, and whether leaks are urge-related versus activity-related 1, 5
Measure post-void residual urine (any method) to exclude overflow incontinence; normal is <200-300 mL 6, 5
Perform urinalysis to exclude urinary tract infection as a reversible cause 3, 5
A focused pelvic examination should assess for neurologic abnormalities and exclude significant pelvic organ prolapse 3
Urodynamic testing is NOT required for initial diagnosis but may be considered for refractory cases or when diagnosis remains unclear after initial evaluation 1, 5
First-Line Management
Behavioral therapies should be offered as first-line treatment to all patients with urge incontinence before pharmacotherapy 1:
Bladder training (extending time between voids) is the cornerstone behavioral intervention 3, 1
Fluid management and caffeine reduction 1
Pelvic floor muscle exercises/training 1
These interventions should be attempted for at least 8-12 weeks before escalating therapy 3, 1
Second-Line Pharmacotherapy
If symptoms persist despite adequate behavioral therapy (typically after 3 months), initiate pharmacologic treatment with antimuscarinic agents or β3-agonists 1:
Antimuscarinic agents (e.g., tolterodine, oxybutynin) are established first-line pharmacotherapy 1, 7
β3-agonists (e.g., mirabegron 25-50 mg daily) are equally effective alternatives, with efficacy demonstrated within 4-8 weeks and significant reductions in incontinence episodes and micturition frequency 1, 8
Combination of behavioral therapy with pharmacotherapy may be used for enhanced efficacy in patients with inadequate response to monotherapy 1
Important Clinical Pitfalls
Do NOT use systemic pharmacologic therapy for pure stress incontinence—medications are ineffective for stress UI and should only be used for urge or mixed incontinence 6
In mixed urinary incontinence (both stress and urge components), treat the most bothersome component first 1, 2
A normal urodynamic study does NOT rule out urge incontinence; the absence of detrusor overactivity on a single test should be interpreted cautiously 1
Patients with neurogenic detrusor overactivity (from conditions like multiple sclerosis or spinal cord injury) require more aggressive treatment to prevent upper urinary tract deterioration 9