Hyperactive Bladder

Hyperactive (overactive) bladder is a symptom syndrome of urinary urgency, usually with frequency and nocturia, with or without urgency urinary incontinence, in the absence of infection or other obvious pathology.

• Prevalence is about 12 to 17 percent of adults, rising with age; both sexes are affected (urge incontinence is more common in women).
• Mechanisms: detrusor overactivity, increased bladder sensory afferent activity, urothelial dysfunction, and altered central control.
• Causes and associations: idiopathic, benign prostatic obstruction, neurological disease (stroke, Parkinson disease, multiple sclerosis, spinal cord disease, dementia), diabetes, obesity, menopause, high caffeine and fluid intake, diuretics, constipation, pelvic floor disorders.

Sudden compelling desire to void that is difficult to defer, urinary frequency (8 or more voids daily), nocturia (waking 2 or more times), urge incontinence.

• Social embarrassment, sleep disturbance, falls and fractures (nocturia in the elderly), skin irritation, depression.
• Differential diagnosis: urinary tract infection, bladder stones or tumour, interstitial cystitis (bladder pain), benign prostatic hyperplasia, polyuria (diabetes mellitus and insipidus, hypercalcaemia), stress incontinence, urethral stricture, pelvic organ prolapse, neurogenic bladder, tuberculous cystitis, schistosomal cystitis, overflow incontinence, medication effects.
• Complications: falls, recurrent urinary infections, perineal dermatitis, sleep loss, social isolation, reduced work productivity, anxiety and depression.

History, bladder diary for 3 days (fluid intake, voids, urgency, leaks), medications, bowel function, neurological and pelvic examination, rectal and prostate examination.

• Urinalysis and culture (exclude infection, blood, glucose, protein); haematuria needs cystoscopy and imaging.
• Post-void residual by ultrasound (above 150 mL suggests retention); serum creatinine, glucose, calcium; PSA when relevant.
• Urodynamics and cystoscopy only for diagnostic uncertainty, failure of initial treatment, neurological disease, or before surgery.
• Pelvic floor assessment in women.

Supportive (for all patients, started first):

• Bladder training with timed voiding, increasing intervals by 15 minutes weekly to 3 to 4 hours; urge suppression techniques (pelvic floor contraction); pelvic floor exercises (3 sets of 8 to 12 contractions daily).
• Fluids 1.5 to 2 L daily (not more), reduce caffeine, alcohol and carbonated drinks; avoid evening fluids; weight loss in obesity; treat constipation; stop smoking.

Pharmacological

• Antimuscarinics: oxybutynin 2.5 to 5 mg two to three times daily (immediate release; maximum 20 mg daily; extended release 5 to 30 mg daily), tolterodine 2 mg twice daily (extended release 4 mg daily), solifenacin 5 mg daily increasing to 10 mg, darifenacin 7.5 mg increasing to 15 mg daily, fesoterodine 4 to 8 mg daily, trospium 20 mg twice daily; start low, assess at 4 weeks.
• Beta-3 agonists: mirabegron 25 mg daily increasing to 50 mg daily (monitor blood pressure), vibegron 75 mg daily; better tolerated in the elderly.
• Side effects of antimuscarinics: dry mouth, constipation, blurred vision, cognitive impairment, urinary retention; avoid in narrow angle glaucoma, gastric retention, and use cautiously in elderly with dementia (prefer mirabegron or trospium).
• Combination therapy (solifenacin 5 mg with mirabegron 50 mg) for incomplete response.
• Postmenopausal women: vaginal oestrogen (oestradiol 10 microgram vaginal tablet daily for 2 weeks then twice weekly, or estriol 0.5 mg cream).
• Nocturia from nocturnal polyuria: desmopressin 25 to 50 microgram sublingually at night (check sodium at 3 days and 1 month; contraindicated in hyponatraemia, heart failure, age over 65 with cardiac or renal disease).
• Men with benign prostatic hyperplasia: tamsulosin 0.4 mg daily with antimuscarinic added after confirming residual urine is low.

Procedures (refractory to drugs):

• Intradetrusor onabotulinumtoxinA 100 units by cystoscopy (effect 6 to 9 months; risk of retention and need for catheterisation), percutaneous tibial nerve stimulation (12 weekly sessions of 30 minutes), sacral neuromodulation, augmentation cystoplasty (rare).

Special groups: elderly (avoid strongly anticholinergic drugs), neurological disease (specialist assessment and catheterisation), pregnancy (behavioural therapy), men with obstruction (treat obstruction first).

Red flags: haematuria, pain, recurrent infection, retention, neurological deficit, pelvic mass, residual urine above 150 mL.

Follow-up: review at 4 to 6 weeks (response, adverse effects), then every 6 to 12 months; stop drugs after 3 to 6 months to test whether they are still needed; continue behavioural therapy.