Overactive Bladder - What is it, and Who has it?
Definitions
- OAB: urgency +/- frequency, nocturia, and urge incontinence
- Urgency: sudden compelling desire to pass urine that is difficult to defer
- Frequency: > 7 voids during the day
- Nocturia: 1+ nocturnal voids
- Nocturnal polyuria: large production of urine during sleep, > 20% if younger, > 33% if older
- Polydipsia: normal/large volume voids (OAB causes small volume voids)
- Urge incontinence: involuntary urine leakage associated with sudden desire to void
- Interstial Cystitis + Bladder Pain: may have frequency/urgency, pain is prime symptom (no pain in OAB)
History
- Storage symptoms: frequency, urgency, urge incontinence, nocturia
- Voiding symptoms: hesitancy, straining, retention, stream strength, intermittency
- Fluid intake habits: types, volume, void diary
- Degree of bother
- PMHx: neuro diseases, mobility issues, DM, BM habits, pelvic pain, rUTIs, hematuria, pelvic cancers, pelvic XRT, prolapse
- PSHx: pelvic surgery
- Meds: diuretics
Physical
- Abdominal exam: scars, masses, hernias, SP distension
- Lower extremities: edema - fluid overload
- Pelvic exam: atrophic vaginitis, prolapse, stress incontinence, pelvic floor dysfunction
- Cognitive function
Adjuncts
- Symptom questionnaires; UDI, UDI-6, II-Q, OAB-q
- Obtain UA, consider separate workup if evidence of hematuria or UTI
- PVR and urine culture not required for uncomplicated patients
- CT/US, urodynamics, and cystoscopy are not required for uncomplicated patients
First Line Therapies: Non-Med/Surg
Behavioral
- Bladder training, delayed voids, scheduled voids, double voids
- Pelvic floor muscle training
- Diet changes, minimizing irritants
- Weight loss: 8% weight loss in obese women decreased incontinence by 47% (vs 28%)
No Treatment?
- Consider other management strategies in elderly or demented patients
- Consider managing functional incontinence
Second Line Therapies: Medications
Anticholinergics
- Mechanism: inhibit bladder contractions (stimulated by parasympathetic signals)
- Options: oxybutynin (Ditropan), solifenacin (Vesicare), darifenacin
- Extended release and transdermal have lower side effect profiles
- Different medications have different side effect risks
- Side effects: dry mouth (20-60%), constipation (7-17%), dry eyes, blurred vision, dyspepsia, UTI, retention, impaired cognition, arrhythmias (rare)
- Manage side effects first with OTC therapies prior to stopping anticholinergic
- May cause synergistic effect with other anticholinergics - TCAs, Parkinson meds, Alzheimer meds
- Contraindications: narrow angle glaucoma, impaired gastric emptying, urinary retention
- Increased risk of side effects (including cognitive deficits) in elderly/frail patients
Mirabegron (Beta-3 Agonists)
- Mechanism: increases sympathetic signals causing bladder relaxation
Does not prolong QT interval
- Similar efficacy to anticholinergics
- Side effects: same rates of dry mouth (lower than anticholinergics), retention, HTN, and arrhythmias as placebo
- Synergy trial (Herschorn 2017): can combine B3 agonist and anticholinergics for improved effect
Third Line Therapies: Interventions
Botox (intravesical botulinum toxin)
- Inject 100U for non-NGB, 200U if NGB
- Injections are temporary and need to be repeated q6-12mo
- Patients need to be willing to provide PVRs and perform CIC if having urinary retention
- Side effects: UTI (4-55%), retention (0-43%)
Sacral Neuromodulation
- Signal generator implanted with lead in S3 foramen, modulates signals causing improved symptoms
- Older models are not MRI compatible, newer models are
- Patients may also have improvement in sexual dysfunction and fecal incontinence
- Side effects: pain at simulator site (3-20%), pain at lead site (4.5-19%), lead migration (1-8.6%, infection/irritaton (2-14%), electric shock (5.5-10%), need for surgical revision (6-39.5%)
Percutaneous Tibial Nerve Stimulation
- 30 minute treatments in clinic x12 weeks, then as individually needed
- 71% improvement (>50% symptom reduction) vs 0% in placebo
- Patients report minimal side effect, main issue is frequent clinic visits
Fourth Line Therapies: Surgery
Enterocystoplasty (bladder augmentation) and urinary diversion can be performed for refractory OAB, but these surgeries are becoming more rare as more conservative medical and surgical therapies are utilized.
Sources
- Gormley, E. Ann, et al. "Diagnosis and treatment of overactive bladder (non-neurogenic) in adults: AUA/SUFU guideline." The Journal of urology 188.6S (2012): 2455-2463.
- Herschorn, Sender, et al. "Efficacy and safety of combinations of mirabegron and solifenacin compared with monotherapy and placebo in patients with overactive bladder (SYNERGY study)." BJU international 120.4 (2017): 562-575.