Treatment of Overactive Bladder
The treatment of overactive bladder (OAB) should follow a menu-based approach rather than a strict stepwise progression, with behavioral therapies offered as first-line treatment to all patients with OAB due to their excellent safety profile and effectiveness comparable to pharmacologic options. 1, 2
Initial Evaluation
- Comprehensive medical history focusing on bladder symptoms (urgency, frequency, nocturia, incontinence) is essential for proper diagnosis and treatment planning 1
- Physical examination should be conducted to identify contributing factors such as pelvic organ prolapse or enlarged prostate 1
- Urinalysis should be performed to exclude microhematuria and infection 1
- Post-void residual (PVR) measurement is indicated in patients with risk factors such as obstructive symptoms, history of retention, neurologic disorders, or prior incontinence/prostate surgery 1, 2
Treatment Categories
1. Behavioral Therapies (First-Line)
- Bladder training, including timed voiding and gradual extension of voiding intervals, should be offered to all patients 1, 2
- Pelvic floor muscle training to improve urge suppression techniques is highly effective 2, 3
- Fluid management with optimization of timing and volume of fluid intake is essential 1, 2
- Dietary modifications, including avoidance of bladder irritants (caffeine, alcohol), can significantly reduce symptoms 1, 2
- Weight loss for obese patients (goal of 8% weight loss) can reduce urgency incontinence episodes by up to 42% 1, 3
2. Pharmacologic Therapies
Beta-3 adrenergic agonists (mirabegron) are typically preferred over antimuscarinics due to their lower cognitive risk 2, 4
- Starting dose: 25 mg once daily
- Maximum dose: 50 mg once daily after 4-8 weeks if needed
- Indicated for OAB with symptoms of urge urinary incontinence, urgency, and frequency
Antimuscarinic medications are effective alternatives but have more side effects 1, 2, 5
- Options include darifenacin, fesoterodine, oxybutynin, solifenacin, tolterodine, or trospium
- Use with caution in patients with narrow-angle glaucoma, impaired gastric emptying, cognitive impairment, or history of urinary retention
- Avoid in patients with PVR >250-300mL
Combination of behavioral and pharmacologic therapies may provide better outcomes than either alone 1, 3
3. Minimally Invasive Therapies (For Refractory Cases)
- Botulinum toxin injection into the bladder is effective for patients who fail behavioral and pharmacologic therapies 5, 6
- Neuromodulation options include:
4. Invasive Therapies (Last Resort)
Special Considerations
- Antimuscarinic medications should be used with caution in elderly patients or those with cognitive impairment risk 2, 3
- For patients with renal impairment (eGFR 15-29 mL/min/1.73 m²), mirabegron dosage should be limited to 25 mg once daily 4
- For patients with moderate hepatic impairment (Child-Pugh Class B), mirabegron dosage should be limited to 25 mg once daily 4
Treatment Expectations
- Most patients experience significant symptom reduction rather than complete resolution 1, 8
- Treatment success should be measured by improvement in quality of life and reduction in symptom burden 1, 2
- Continuation rates for pharmacologic therapy are often low, emphasizing the importance of patient education on treatment efficacy and realistic expectations 5