Patients with overactive bladder typically have a variety of symptoms that may include urinary urgency and frequency, nocturia, and urge incontinence. The condition is frequently encountered and affects an estimated 30 to 40 percent of persons 75 years of age or older. Patients with symptoms of overactive bladder often withdraw from their usual social activities, are more likely to be depressed, and may suffer from sleep disruption because of nocturia. Ouslander provides a review of the diagnostic work-up and treatment of overactive bladder.
Urination is a complex process, involving the higher cortex of the brain, the brainstem, afferent and efferent neural pathways, and various anatomic structures of the lower urinary tract. Problems in any of these areas can lead to bladder dysfunction; the review includes a detailed table of conditions that may be implicated in overactive bladder.
Overactive bladder has a multifactorial etiology in most persons. The author states that a targeted diagnostic evaluation of patients with symptoms of overactive bladder is required. All older men should be questioned about symptoms of benign prostatic hypertrophy. Patient diaries may provide helpful details regarding frequency of urination, voiding volumes, pattern of voiding, and lifestyle factors that may contribute to symptoms. All patients should have focused genitourinary, pelvic, and rectal examinations, and a clean-catch urine specimen should be checked for hematuria and infection.
Sterile in-and-out catheterization can be used to check for the presence of post-void residual urine, and this procedure should be considered in patients at risk for urinary retention (such as those with diabetes, benign prostatic hypertrophy, or spinal cord injury). Alternatively, ultrasonography provides a noninvasive way to measure post-void bladder volumes. Cystoscopy should be targeted to patients with unexplained hematuria, recurrent urinary tract infections, or risk factors for bladder cancer. Urodynamic testing is relatively more complex and invasive, and the author notes that its role in the diagnostic work-up of overactive bladder is controversial. He suggests targeting this procedure to patients who have failed initial therapy or those with nonspecific symptoms and an unclear etiology of overactive bladder.
The multifactorial causes of bladder dysfunction typically necessitate a multimodal approach to treatment that includes behavioral and pharmacologic interventions. All patients should be educated to limit caffeine intake (and other diuretics, when possible), avoid constipation, and plan fluid intake to minimize social disruptions and sleep disturbance. Pelvic-muscle floor exercises and “bladder training” are more likely to be effective in cognitively intact, motivated patients whose primary problem is incontinence.
Anticholinergic medications are the mainstay of drug therapy for overactive bladder. The chief problems occurring with these medications are side effects and incomplete efficacy. The most common side effect is dry mouth, and constipation, gastroesophageal reflux, blurred vision, urinary retention, and cognitive problems also may occur. Of the many agents available, oxybutynin and tolterodine have the most evidence for clinical efficacy. Generic immediate-release oxybutynin may work best in patients who only need short-term control such as during social situations or at night to decrease nocturia. The once-daily controlled-release form of oxybutynin has fewer reported side effects and similar efficacy. Tolterodine is also available in short-acting and long-acting formulations, with similar efficacy and side effects compared with oxybutynin.
Older men with prostatic hypertrophy may benefit from alpha-blocker medications and should be watched for urinary retention if anticholinergic drugs are employed. Nocturia related to volume overload (e.g., venous insufficiency, congestive heart failure with peripheral edema) may be improved by one dose of a diuretic taken in the late afternoon or by nighttime use of desmopressin in children. The review discusses a number of investigational medications, which may have promise for treatment of overactive bladder.