Chapter 42: Urinary Incontinence

Urinary incontinence is the involuntary loss of urine that is so severe as to have social or hygienic consequences. A basic understanding of the normal physiology of urination is important to understand the potential causes of incontinence, and the various strategies for effective treatment.

The lower urinary tract consists primarily of the bladder (detrusor muscle) and the urethra. The urethra contains two sphincters: the internal urethral sphincter (IUS), composed predominantly of smooth muscle, and the external urethral sphincter (EUS), which is primarily voluntary muscle. The detrusor muscle of the bladder is innervated predominantly by cholinergic (muscarinic) neurons from the parasympathetic nervous system, the stimulation of which leads to bladder contraction. The sympathetic nervous system innervates both the bladder and the IUS. Sympathetic innervation in the bladder is primarily β-adrenergic and leads to bladder relaxation, whereas α-adrenergic receptors predominate in the IUS, leading to sphincter contraction. Thus, in general, sympathetic stimulation promotes bladder filling (relaxation of the detrusor with contraction of the sphincter), whereas parasympathetic stimulation leads to bladder emptying (detrusor contraction and sphincter relaxation).

The EUS, on the other hand, is striated muscle and under primarily voluntary (somatic) control. This allows for some ability to voluntarily postpone urination by tightening the sphincter and inhibiting the flow of urine. Additional voluntary control is provided by the central nervous system (CNS) through the pontine micturition center. This allows for central inhibition of the autonomic processes described earlier, and for further voluntary postponement of the need to urinate until the circumstances are more socially appropriate or until necessary facilities are available.

The physiologic factors influencing normal urination, summarized in Table 42-1, are important considerations when discussing urinary disorders and treatment.

Contrary to common perception, urinary incontinence is not inevitable with aging. Most elderly patients remain continent throughout their lifetimes, and a complaint of incontinence at any age should receive a thorough evaluation and not be dismissed as “normal for age.” Nonetheless, many common age-related changes predispose elderly patients to incontinence and increase the likelihood of its development with advancing age.

The frequency of involuntary bladder contractions (detrusor hyperactivity) increases in both men and women with aging. In addition, total bladder capacity decreases, causing the voiding urge to occur at lower volumes. Bladder contractility decreases, leading to increased postvoid residuals and increased sensation of urgency or fullness. Elderly patients excrete a larger percentage of their fluid volume later in the day than younger persons. This, in addition to the other changes listed, often leads to an increase in the incidence of nocturia with aging, and more frequent nighttime awakenings.

In women, menopausal estrogen decline leads to urogenital atrophy and a decrease in the sensitivity of α-receptors in the IUS. In men, prostatic hypertrophy can lead to increased urethral resistance, and varying degrees of urethral obstruction.

It is important to remember that these age-related changes are found in many healthy, continent persons as well as those who develop incontinence. It is not completely understood why the predisposition to urinary problems is stronger in some patients than in others, which emphasizes the multifactorial basis of incontinence.

Clinical Findings

A. Symptoms and Signs

1. Incontinence outside the urinary tract

Incontinence is often classified according to whether it is related to specific urogenital pathology or to factors outside the urinary tract. Terms such as transient versus established, acute versus persistent, and primary versus secondary have been used to highlight this distinction. The mnemonic DIAPPERS is helpful in remembering the many causes of incontinence that occur outside the urinary tract (Table 42-2). These “extraurinary” causes are very common in the elderly, and it is important to identify or rule them out before proceeding to a more invasive search for primary urogenital etiologies.

Delirium, depression, and disorders of excessive urinary output generally require medical or behavioral management of the primary cause rather than strategies relating to the bladder. Once the primary causes are corrected, the incontinence often resolves. Urinary tract infections, although easily treated if discovered, are a relatively infrequent cause of urinary incontinence in the absence of other classic symptoms (dysuria, urgency, frequency, etc). Asymptomatic bacteriuria, which is common even in well elderly, does not cause incontinence.

Pharmaceuticals are a particularly important and very common cause of incontinence. Because of the many neural receptors involved in urination (see Table 42-1), it is easy to understand why so many medications used to treat other common problems can readily affect continence. Medications frequently associated with incontinence are listed in Table 42-3. Many of these medications are available over the counter and in combination (Table 42-4). In addition, commonly used substances such as caffeine and alcohol can contribute to incontinence by virtue of their diuretic effects or their effects on mental status. For this reason, some medications and substances associated with a patient’s incontinence may not be considered important or readily volunteered during a medication history unless the physician specifically asks about them.

Restricted mobility or the inability to physically get to the bathroom in time to avoid incontinence is also referred to as “functional” incontinence. The incontinence may be temporary or chronic, depending on the nature of the physical or cognitive disability involved. Physical therapy or strength and flexibility training may be helpful, as well as simple measures such as a bedside commode or urinal.

Stool impaction is very common in the elderly and may cause incontinence either through its local mass effect or by stimulation of opioid receptors in the bowel. It has been reported to be a causative factor in ≤10% of patients referred to incontinence clinics for evaluation. Continence can often be restored by a simple disimpaction.

2. Urologic causes of incontinence

Once secondary or transient causes have been investigated and ruled out, further evaluation should focus on specific urologic pathology that may be causing incontinence.

The urinary tract has two basic functions: the emptying of urine during voiding and the storage of urine between voiding. A defect in either of these basic functions can cause incontinence, and it is useful to initially classify incontinence according to whether it is primarily a defect of storage or of emptying. An inability to store urine occurs when the bladder contracts too often (or at inappropriate times), or when the sphincter(s) cannot contract sufficiently to allow the bladder to store urine and keep it from leaking. Thus the bladder rarely, if ever, fills to capacity and the patient’s symptoms are generally characterized by frequent incontinent episodes of relatively small volume. An inability to empty urine occurs when the bladder is unable to contract appropriately, or when the outlet or sphincter(s) is (are) partially obstructed (either physically or physiologically). Thus, the bladder continues to fill beyond its normal capacity and eventually overflows, causing the patient to experience abdominal distention and continual or frequent leakage.

Whether the primary problem is the inability to store or the inability to empty can often be determined easily during the history and physical examination according to the patient’s incontinence pattern (intermittent or continuous) and whether abdominal (bladder) distention is present. Determination of postvoid residual is also helpful in making this distinction (see section on history and physical findings, later). This initial classification is important in narrowing down the specific etiology of the incontinence, and in ultimately deciding on the appropriate management strategy.

3. Symptomatic classification

Once it is determined whether the primary problem is with storage or with emptying, incontinence can be further classified according to the type of symptoms that it causes in the patient. The most common categories are discussed below. The first two types, urge incontinence and stress incontinence, result from an inability to store urine. The third type, overflow incontinence, results from an inability to empty urine. Because the term “overflow” has been widely deemed confusing and imprecise, the terms incomplete bladder emptying and urinary retention are now often used instead. A patient may have a single type of incontinence or a combination of more than one type (mixed incontinence). Table 42-5 summarizes the major categories of incontinence, the underlying urodynamic findings, and the most common etiologies for each.

A. urge incontinence

Urge incontinence is the most common type of incontinence in the elderly. Patients complain of a strong, and often immediate, urge to void followed by an involuntary loss of urine. It is rarely possible to reach the bathroom in time to avoid incontinence once the urge occurs, and patients often lose urine while rushing toward a bathroom or trying to locate one. Urge incontinence is most frequently caused by involuntary contractions of the bladder, often referred to as detrusor instability. These involuntary contractions increase in frequency with age, as does the ability to voluntarily inhibit them. Although the symptoms of urgency are a hallmark feature of this type of incontinence, detrusor instability can sometimes result in incontinence without these symptoms. Although most patients with detrusor instability are neurologically normal, uninhibited contractions can also occur as the result of neurologic disorders such as stroke, dementia, or spinal cord injury. In these cases it is often referred to as detrusor hyperreflexia. Detrusor instability and urgency can also be caused by local irritation of the bladder as with infection, bladder stones, or tumors. The term overactive bladder syndrome (OABS) is now commonly used to describe the symptoms of urgency caused by detrusor instability and to emphasize that they can occur either with or without incontinence. OABS is described by the International Continence Society as voiding ≥8 times during a 24-hour period, and awakening ≥2 times during the night. Treatment of OABS is similar regardless of whether incontinence is present.

B. stress incontinence

Stress incontinence is much more common among women than men and is defined as a loss of urine associated with increases in intraabdominal pressure (Valsalva maneuver). Patients complain of leakage of urine (usually small amounts) during coughing, laughing, sneezing, or exercising. In women, stress incontinence is most often caused by urethral hypermobility resulting from weakness of the pelvic floor musculature, but it can also be caused by intrinsic weakness of the urethral sphincter(s), most commonly following trauma, radiation, or surgery. Stress incontinence is rare in men, unless they have suffered damage to the sphincter through surgery or trauma. In diagnosing stress incontinence, it is important to ascertain that the leakage occurs exactly coincident with the stress maneuver. If the leakage occurs several seconds after the maneuver, it is more likely caused by an uninhibited bladder contraction that has been triggered by the stress maneuver, and is urodynamically more similar to urge incontinence. This is sometimes known as stress-induced detrusor instability.

C. incomplete bladder emptying (overflow incontinence)

This is a loss of urine associated with overdistention of the bladder. Patients complain of frequent or constant leakage or dribbling, or they may lose large amounts of urine without warning. Incomplete emptying may result either from a defect in the bladder’s ability to contract (detrusor hypoactivity) or from obstruction of the bladder outlet or urethra. Detrusor hypoactivity is most commonly the result of a neurogenic bladder secondary to diabetes mellitus, chronic alcoholism, or disk disease. It can also be caused by medications, primarily muscle relaxants and β-adrenergic blockers. Outlet obstruction can be physical (prostatic enlargement, tumor, stricture), neurologic (spinal cord lesions, pelvic surgery), or pharmacologic (α-adrenergic agonists). Because neurogenic bladder is relatively rare in the geriatric population, it is important to rule out possible causes of obstruction whenever the diagnosis of overflow incontinence is made.

D. functional incontinence

The term functional incontinence is used to describe physical or cognitive impairments that interfere with continence even in patients with normal urinary tracts (see section on incontinence outside the urinary tract, Table 42-2, and the DIAPPERS mnemonic, earlier).

E. mixed incontinence

Mixed incontinence describes various combinations of the preceding four types. When present, it can make the diagnosis and management of incontinence more difficult. The term is most frequently used to describe patients who present with a combination of stress and urge incontinence, although other combinations are also possible. Functional incontinence, for example, can coexist with stress, urge, or overflow incontinence, further complicating the treatment of these patients. Side effects of medications being used to treat other comorbidities can also cause a mixed picture when combined with underlying incontinence of any type. Mixed stress and urge incontinence is particularly common among elderly women. When present, it is helpful to focus on the symptom that is most bothersome to the patient, and to direct the initial therapeutic interventions in that direction.

B. Screening

Screening for incontinence in all women is recommended because of its high prevalence and low degree of self-reporting by patients. Elderly women and those with neurologic diseases or diabetes are at the highest risk. Screening women aged ≥65 years for urinary incontinence is one of the quality reporting measures adopted by the Centers for Medicare and Medicaid Services in their 2013 Physician Quality Reporting System (PQRS) initiative, as is characterizing the type of incontinence and developing a plan of care.

C. History and Physical Findings

The history and physical examination of a patient presenting with incontinence should have the following goals:

1. To evaluate for and rule out causes of incontinence outside the urinary tract (DIAPPERS)

2. To determine whether the primary defect is an inability to store urine or an inability to empty urine

3. To determine the type of incontinence according to the patient’s symptoms and likely etiologies

4. To determine the pattern of incontinence episodes and its effect on the patient’s functional ability and quality of life

1. History

A thorough medical history should include a special focus on the neurologic and genitourinary history of the patient as well as any other medical problems that may be contributing factors (see Table 42-2). Information on any previous evaluation(s) for incontinence, as well as their degree of success or failure, can be helpful in guiding the current evaluation and in determining patient expectations. A careful medication history is very important, focusing on the categories of medications listed in Table 42-3 and remembering to include nonprescription substances (see Table 42-4). Finally, the pattern of incontinence is important in helping to classify its type and in planning appropriate therapy. While many urinary symptoms (eg, dribbling, frequency, hesitancy, nocturia) may lack diagnostic specificity, symptoms of urgency (the sudden urge to void with leakage before reaching the toilet) are very sensitive and specific for the diagnosis of urge incontinence. Urine leakage with coughing or other stress maneuvers is a sensitive indicator of stress incontinence, but is less specific than urge because of overlap with other conditions. A voiding diary or bladder record can be a very useful tool in obtaining additional diagnostic information. The patient or caregiver is given a set of forms and is asked to keep a written record of each incontinent episode for several days. A sample form is shown in Table 42-6. Incontinent episodes are recorded in terms of time, estimated volume (small or large), and precipitating factors. Fluid intake, as well as any episodes of urination in the toilet, is also recorded. When completed accurately, the bladder record can often elucidate the most likely type of incontinence and provide a clue to possible precipitating factors. Continuous leakage, for example, may be more consistent with overflow incontinence, whereas multiple, large-volume episodes may be more consistent with urge. Smaller-volume episodes associated with coughing or exercise may be more consistent with stress incontinence, whereas incontinence occurring only at specific times each day may suggest an association with a medication or other non–urinary tract cause. Although other information from the physical and laboratory evaluations will obviously be needed, the physician can often make significant progress toward determining the type of incontinence and possible precipitating factors from the history and voiding record alone.

2. Physical examination

In addition to a thorough search for nonurologic causes of incontinence, the physical examination should focus on the cardiovascular, abdominal, genital, and rectal areas. Cardiovascular examination should focus on signs of fluid overload. Evidence of bladder distention on abdominal examination should raise suspicion for overflow incontinence. Genital examination should include a pelvic examination in women to assess for evidence of atrophy or mass, as well as any signs of uterine prolapse, cystocele, or rectocele. A rectal examination is helpful in ruling out stool impaction or mass, as well as in evaluating sphincter tone and perineal sensation for evidence of a neurologic deficit. A prostate examination is usually included, but several studies have demonstrated a poor correlation between prostate size and urinary obstruction. A neurologic examination focusing on the lumbosacral area is helpful in ruling out a spinal cord lesion or other neurologic deficits.

3. Special tests

Two additional tests, specific to the diagnosis of incontinence, should be added to the general physical examination.

A. provocative stress testing

This test attempts to reproduce the symptoms of incontinence under the direct visualization of the physician and is useful in differentiating stress from urge incontinence. The patient should have a full bladder and preferably be in a standing position (although a lithotomy position is also acceptable for patients unable to stand). The patient should be told to relax, and then to cough vigorously while the physician observes for urine loss. If leakage occurs simultaneously with the cough, a diagnosis of stress incontinence is likely. A delay between the cough and the leakage is more likely caused by a reflex bladder contraction and is more consistent with urge incontinence.

B. postvoid residual (PVR)

This measurement should be obtained for incontinent patients suspected of urinary retention and potential obstruction. This includes men with severe urinary symptoms, women with prior gynecological or pelvic surgery, persons with neurological disorders or diabetes, and those who have failed initial empiric therapy. PVR measurement is traditionally done by urinary catheterization; however, portable ultrasound scanners for this purpose are now available that also provide very accurate readings. These ultrasound devices minimize the risks of instrumentation and infection that are inherent in catheterization, especially in male patients. Prior to measurement, the patient should be asked to empty the bladder as completely as possible. Residual urine in the bladder should be measured within a few minutes after emptying using either in-and-out catheterization or ultrasound. A PVR of <50 mL is normal; >200 mL indicates inadequate bladder emptying and is consistent with overflow incontinence. PVRs between 50 and 199 mL can sometimes be normal but may also exist with overflow incontinence, and results should be interpreted in light of the clinical picture. Patients with elevated PVRs should generally be referred for further evaluation and to rule out obstruction prior to treatment of the incontinence symptoms.

C. other diagnostic maneuvers

Other maneuvers, or “bedside urodynamics,” have often been recommended to help in the diagnosis of incontinence. The best known of these are the Q-tip test to diagnose pelvic laxity and the Bonney (Marshall) test to determine whether surgical intervention will be helpful. Although these tests may be useful in some settings, recent studies have cast doubt on their predictive value, and in the family practice setting they are unlikely to add clinically useful information that would help in sorting out the small percentage of patients whose diagnosis remains unclear after a thorough history and physical examination.

C. Laboratory and Imaging Evaluation

Like the history and physical examination, the laboratory evaluation should be focused on ruling out the nonurologic causes of incontinence. A urinalysis is very helpful in screening for infection as well as in evaluating for hematuria, proteinuria, or glucosuria. It must be remembered, however, that asymptomatic bacteriuria is very common in the elderly and is not a cause of incontinence. Antibiotic treatment of asymptomatic bacteriuria has not been shown to reduce morbidity or to improve incontinence in either the institutionalized elderly or ambulatory women. Thus, antibiotic treatment in the face of incontinence and bacteriuria should be reserved for patients whose incontinence is of recent onset, has recently worsened, or is accompanied by other signs of infection. Hematuria, in the absence of infection, should be referred for further evaluation to rule out carcinoma.

Additional laboratory studies that are recommended and may be helpful include measurement of renal function [blood urea nitrogen (BUN) and creatinine] and evaluation for metabolic causes of polyuria (hypercalcemia, hyperglycemia). Radiologic studies are not routinely recommended in the initial evaluation of most patients with incontinence; however, a renal ultrasound study is useful in patients with obstruction to evaluate for hydronephrosis.

Treatment

If nonurologic or functional causes are found as major contributors to the patient’s incontinence, treatment should be targeted at the underlying illnesses and improving any functional disability. In addition to medical management of the underlying disorder(s), physical therapy and the use of assistive devices may be helpful in improving the patient’s level of function and ability to reach the bathroom prior to having an incontinent episode. For the ambulatory patient, a home visit is often useful in assessing for any environmental hazards that may be contributing to functional incontinence.

Simple lifestyle modifications may be helpful in mild cases of urinary incontinence. Fluid restriction and avoidance of caffeine and alcohol, especially in the evening, can be recommended as an initial step. Weight loss can be recommended if the patient is obese, and the use of a bedside commode or urinal can also be helpful. For patients with more severe incontinence, however, including most patients with urologic causes, further treatment measures usually are necessary.

Treatment for urinary incontinence is divided into three categories: behavioral and nonpharmacologic therapies, pharmacotherapy, and surgical intervention.

A. Behavioral and Nonpharmacologic Therapies

Lifestyle measures and behavioral therapies should be the first-line treatments in most patients with urge or stress incontinence, as they have the advantages of being effective in a large percentage of patients with few, if any, side effects. Lifestyle measures include limiting excessive fluid intake, avoiding caffeinated and alcoholic beverages, and attaining a healthy weight. Weight loss in overweight and obese women has been shown to be effective in reducing episodes of stress incontinence, but urge incontinence was not decreased. Behavioral therapies range from those designed to treat the underlying problem and restore continence (eg, bladder training, pelvic muscle exercises) to those designed simply to promote dryness through increased attention from a caregiver (eg, timed voiding, prompted voiding). The former category requires a motivated patient who is cognitively intact, whereas the latter category can be used even in patients with significant cognitive impairment.

1. Bladder training

This technique is designed to help patients control their voiding reflex by teaching them to void at scheduled times. The patient is asked to keep a voiding record for approximately 1 week to determine the pattern of incontinence and the interval between incontinent episodes. A voiding schedule is then developed with a scheduled voiding interval significantly shorter than the patient’s usual incontinence interval. (For example, if the usual time between incontinent episodes is 1–2 hours, the patient should be scheduled to void every 30–60 minutes.) The patient is asked to empty the bladder as completely as possible at each scheduled void regardless of whether an urge is felt. Patients who have the urge to void at unscheduled times should try to stop the urge through relaxation or distraction techniques until the urge passes, and then void at the next scheduled time. If the urge between scheduled voids becomes too uncomfortable, the patient should go ahead and void, but should still void again as completely as possible at the next scheduled time. As the number of incontinent episodes decreases, the scheduled voiding intervals should be gradually extended each week, until a comfortable voiding interval is reached.

Fantl and colleagues, in a well-publicized albeit relatively small trial of bladder retraining (Fantl et al. 1991), demonstrated significant improvement in both the number of incontinent episodes and the amount of fluid lost in incontinent elderly women. Although the benefit was greatest in women with urge incontinence, women with stress incontinence also demonstrated improvement. In a later study, their group also demonstrated a significant improvement in quality of life following institution of bladder training. Studies in a family practice setting, in a home nursing program, and in a health maintenance organization also demonstrated significant benefit from a program of bladder training. The latter, a randomized controlled trial published in 2002, included patients with stress, urge, and mixed incontinence. Overall, patients had a 40% decrease in their incontinent episodes with 31% being 100% improved, 41% at least 75% improved, and 52% at least 50% improved.

2. Pelvic muscle exercises

These exercises, also known as Kegel exercises, are designed to strengthen the periurethral and perivaginal muscles. They are most useful in the treatment of stress incontinence but may also be effective in urge and mixed incontinence. Patients are initially taught to recognize the muscles to contract by being asked to squeeze the muscles in the genital area as if they were trying to stop the flow of urine from the urethra. While doing this, they should ensure that only the muscles in the front of the pelvis are being contracted, with minimal or no contraction of the abdominal, pelvic, or thigh muscles. Once the correct muscles are identified, patients should be taught to hold the contraction for at least 10 seconds followed by 10 seconds of relaxation. The exercises should be repeated between 30 and 80 times per day. Patients are then taught to contract their pelvic muscles before and during situations in which urinary leakage may occur to prevent their incontinent episodes from occurring.

A recent systematic review of 43 published clinical trials concluded that pelvic muscle exercises are effective for both stress and mixed incontinence, but that their effectiveness for urge incontinence remains unclear. Biofeedback has been used effectively to improve patients’ recognition and contraction of pelvic floor muscles, but the required equipment and expertise can make this impractical in a primary care setting. Weighted vaginal cones and electrical stimulation have also been used to enhance pelvic muscle exercises. These modalities are provided by many physical therapy or geriatric departments and can be considered as additional options for women who are unsuccessful with pelvic muscle exercises or who have obtained only partial improvement. The Cochrane group concluded that weighted vaginal cones, electrostimulation, and pelvic muscle exercises are probably similar in effectiveness. There was insufficient evidence to conclude that the addition of cones or biofeedback is more effective than pelvic muscle exercises alone. The effectiveness of pelvic muscle exercises has not been well studied in men, but pelvic muscle exercises have been shown to improve incontinence following prostatectomy.

3. Timed voiding

Timed voiding is a passive toileting assistance program that is caregiver-dependent and can be used for patients who are either unable or unmotivated to participate in more active therapies. Its goal is to prevent incontinent episodes rather than to restore bladder function. The caregiver provides scheduled toileting for the patient on a fixed schedule (usually every 2–4 hours), including at night. There is no attempt to motivate the patient to delay voiding or resist the urge to void as there is in bladder training. The technique can be used for patients who can toilet independently as well as those who require assistance. It has been used with success in both male and female patients and has achieved improvements of ≤85%. Timed voiding has also been used effectively in postprostatectomy patients as well as in patients with neurogenic bladder.

A variation of timed voiding, known as habit training, uses a voiding schedule that is modified according to the patient’s usual voiding pattern rather than an arbitrarily fixed interval. The goal of habit training is to preempt incontinent episodes by scheduling the patient’s toileting interval to be shorter than the usual voiding interval. Both timed voiding and habit training are most commonly used in nursing homes but may also be used in the home if a motivated caregiver is available.

4. Prompted voiding

Prompted voiding is a technique that can be used for patients with or without cognitive impairment; it has been studied most frequently in the nursing home setting. Its goal is to teach patients to initiate their own toileting through requests for help and positive reinforcement from caregivers. Approximately every 2 hours, caregivers prompt the patients by asking whether they are wet or dry and suggesting that they attempt to void. Patients are then assisted to the toilet if necessary and praised for trying to use the toilet and for staying dry. A recent systemic analysis of controlled trials of prompted voiding concluded that the evidence was suggestive, although inconclusive, that prompted voiding provided at least short-term benefit to incontinent patients. The addition of oxybutynin to a prompted voiding program may provide additional benefit for some patients. A recent nursing home trial demonstrated that prompted voiding is most effective for reducing daytime incontinence, and that routine nighttime toileting was not effective in reducing incontinent episodes during the night.

B. Pharmacotherapy

Medications may be used alone or in conjunction with behavioral therapy when degree of improvement has been insufficient. There are very few studies comparing drug therapy with behavioral therapy, but both have been found more effective than placebo. An accurate diagnosis of the type of incontinence is necessary in order to choose appropriate pharmacotherapy for each patient.

1. Urge incontinence

Anticholinergic medications are the drugs of choice for urge incontinence, and six medications in a total of 12 formulations are now available. Oxybutynin, the earliest of these medications, is now available in a transdermal patch (Oxytrol) that can be dosed twice weekly, as well as a long-acting formulation (Ditropan XL) and a gel (Gelnique) that can both be dosed once daily. It is also available in a generic formulation that is significantly less expensive, but requires dosing (2.5–5 mg) 2–4 times a day.

Tolterodine is also available in both short-acting (Detrol) and long-acting (Detrol LA) formulations that can be dosed either once or twice daily. No direct trial has yet been published comparing the long-acting forms of the two drugs. A study of long-acting oxybutynin versus short-acting tolterodine found oxybutynin was modestly more effective with a similar side effect profile and cost. A meta-analysis of four comparative trials (studying mainly the short-acting formulations) concluded that oxybutynin is superior in efficacy, but that tolterodine is better tolerated with fewer dropouts because of medication side effects. The most common side effects of anticholinergic medications include dry mouth, blurred vision, constipation, dizziness, and headache. Urinary retention and delirium can also occur. These effects are less common with tolterodine, and dry mouth seems less common with the transdermal and gel formulations of oxybutynin, due to a lower production of metabolite.

Four newer anticholinergic medications have been released to compete with oxybutynin and tolterodine. Trospium (Sanctura), released in 2004, offers the advantage of fewer drug-drug interactions because it is not metabolized by the cytochrome P450 system and is cleared by the kidney. It now has an extended-release formulation available that allows once-daily dosing. Solifenacin (Vesicare) and darifenacin (Enablex), both released in 2005, are more selective for the M3 muscarinic receptors in the bladder than the more traditional agents. Both are dosed once daily. M3 receptors are found preferentially in smooth muscle, the salivary glands, and the eyes. This selectivity may lead to a lower incidence of drowsiness and dizziness in some patients; the most common side effects are dry mouth and constipation. The industry-sponsored STAR trial found solifenacin to be somewhat more effective than tolterodine in reducing urgency and frequency, but dry mouth and constipation were more frequent with solifenacin. Fesoterodine (Toviaz), released in 2009, is similar to Detrol LA and has the same active metabolite. It is supplied in a higher-dose formulation (8 mg) than Detrol, which may increase its efficacy but likely also its side effects.

Mirabegron (Myrbetriq), released in 2012, is the first β₃-agonist, and is marketed for use in overactive bladder syndrome and urge incontinence. Stimulation of β₃-receptors helps to relax the bladder and increase storage capacity, and this drug can be used as an alternative to anticholinergics for patients who don’t tolerate or respond adequately to them. Mirabegron has been shown to slightly increase heart rate and blood pressure, so these parameters should be monitored in patients on this drug. In addition, mirabegron can lead to increased drug levels of digoxin, metoprolol, desipramine, and other medications metabolized by the cytochrome P450-2D6 system. There is no current evidence for the safety of efficacy of combination therapy with mirabegron and any of the anticholinergic medications.

The tricyclic antidepressant imipramine has traditionally been widely used to treat urge incontinence, but its use has now largely been supplanted by these newer agents with more favorable side effect profiles and better documented efficacy.

2. Stress incontinence

Medical treatment is most effective for patients with mild to moderate stress incontinence and without a major anatomic abnormality. The α-agonist pseudoephedrine, at a dosage range of 15–60 mg 3 times a day, is the drug of choice for patients without contraindications. Side effects include nausea, dry mouth, insomnia, and restlessness. Studies using phenylpropanolamine (now removed from the market) demonstrated improvement in 19–60% of women and cure in 9–14%. One study indicated that a significant number of patients referred for surgical intervention could avoid surgery with α-agonist therapy.

Traditionally, estrogen therapy has been used in conjunction with α-agonists to increase α-adrenergic responsiveness and improve urethral mucosa and smooth-muscle tone. However, the recent Heart and Estrogen/Progestin Replacement Study (HERS) demonstrated estrogen therapy to be less effective than placebo for symptoms of urinary incontinence, with only 20.9% of the treatment group reporting improvement and 38.8% reporting worsening of their incontinence (compared with 26% improvement and 27% worsening in the placebo group). Data from the Women’s Health Initiative study, indicating that patients on an estrogen-progestin combination demonstrated increased risk for heart disease, stroke, breast cancer, and pulmonary embolism, also cast significant doubt on the advisability of long-term estrogen use for this indication. Although the risks and benefits of topical estrogen are not completely known, prescription of oral estrogen for the treatment of incontinence is not currently recommended.

3. Overflow incontinence

Overflow incontinence associated with outlet obstruction is seldom treated with medications because the primary therapy is removal of the obstruction. In men, outlet obstruction is most commonly caused by prostatic enlargement secondary to infection (prostatitis), benign prostatic hyperplasia, or prostate cancer. Prostatitis can be treated with a 2–4-week course of a fluoroquinolone or trimethoprim-sulfamethoxazole. Once prostate cancer has been ruled out, benign prostatic hyperplasia may be treated with α-blockers, finasteride, surgery, or transurethral microwave thermotherapy. α-Blockers have been shown to be ineffective in “prostatismlike” symptoms in elderly women.

Medical treatment of overflow incontinence caused by bladder contractility problems is rarely highly efficacious. The cholinergic agonist bethanechol may be useful subcutaneously for temporary contractility problems following an overdistention injury but is generally ineffective when given orally or when used on a long-term basis.

C. Surgical Intervention

Surgical therapy may be indicated for patients with incontinence resulting from anatomic abnormalities (eg, cystocele, prolapse), with outlet obstruction resulting in urinary retention, or for patients in whom more conservative methods of treatment have not provided sufficient relief. Beyond the correction of anatomic abnormalities or obstruction, surgical therapy is most effective for stress incontinence or for mixed incontinence in which stress incontinence is a primary component. Numerous surgical options are available for the management of stress incontinence, including injection of periurethral bulking agents, transvaginal suspensions, retropubic suspensions, slings, and sphincter prostheses. Choice of procedure is based on the relative contributions of urethral hypermobility versus intrinsic sphincter deficiency, urodynamic findings, the need for other concomitant surgery, the patient’s medical condition and lifestyle, and the experience of the surgeon.

D. Electrical Stimulation

These devices are sometimes used to treat incontinence that has been refractory to other methods. The goals are to stimulate contractions of the pelvic floor muscles and/or inhibit overactive bladder contractions. Noninvasive stimulation electrodes can be placed in either the vagina or the anus. Current evidence does not support the efficacy of these methods as being better than behavioral training alone. Electrodes can also be implanted in the sacral nerve roots, the bladder, or the peripheral tibial nerve. These appear to be more effective than noninvasive stimulation, but are reserved for carefully selected patients who have been refractory to less invasive measures.

E. Pads, Garments, Catheterization, and Pessaries

The use of absorbent pads and undergarments is extremely common among the elderly. Although they are not recommended as primary therapy before other measures have been tried, they may be useful in patients whose incontinence is infrequent and predictable, who cannot tolerate the side effects of medications, or who are not good candidates for surgical therapy. The main purpose of these pads and garments is to contain urine loss and prevent skin breakdown. However, very few studies have compared the numerous absorbent products available and their degree of success or failure in meeting these objectives. A recent Cochrane review concluded that disposable products may be more effective than nondisposable products in decreasing the incidence of skin problems, and that superabsorbent products may perform better than fluff pulp products. More comparative studies are needed in this area to assist patients and caregivers in making better-informed decisions.

Although urethral catheterization should be avoided as a general rule, it is sometimes indicated in cases of overflow incontinence or in patients for whom no other measures have been effective. External collection devices (eg, Texas catheters) are preferable to indwelling catheters, but acceptable external devices are not widely available for women, and adverse reactions such as skin abrasion, necrosis, and urinary tract infection may occur. When internal catheterization is needed, intermittent or suprapubic catheterization has been shown to be preferable to indwelling catheterization in reducing the incidence of bacteriuria and its consequent complications. Indwelling urethral catheterization should be limited to very few circumstances, including comfort measures for the terminally ill, for prevention of contamination of pressure ulcers, and for patients with inoperable outflow obstruction.

Pessaries are intravaginal devices used to maintain or restore the position of the pelvic organs in patients with genitourethral prolapse. Although there are few comparative data on their use in incontinence, they can sometimes be useful in patients with intractable stress incontinence who are poor candidates for, or who do not desire, surgery.

F. Primary Care Treatment versus Referral

Once the information from the history, physical examination, voiding record, provocative stress testing, PVR measurement, and laboratory data is available, a presumptive diagnosis can be made in the large majority of patients. If the patient has uncomplicated urge or stress incontinence, or a mixture of urge and stress, primary treatment can be initiated by the family physician. If the patient has overflow incontinence, manifested by an elevated PVR, referral is indicated to rule out obstruction prior to attempting medical or behavioral management. In the minority of patients in whom the type or cause of incontinence remains unclear, referral for urodynamic testing is indicated if a specific diagnosis will be helpful in guiding therapy. Urodynamic testing in the routine evaluation of incontinence is not indicated as studies have not shown an improvement in clinical outcome between patients diagnosed by urodynamics and patients whose treatment was based on history and physical examination.

Other indications for referral include incontinence associated with recurrent symptomatic urinary tract infections, hematuria without infection, history of prior pelvic surgery or irradiation, marked pelvic prolapse, suspicion of prostate cancer, lack of correlation between symptoms and physical findings, and failure to respond to therapeutic interventions as would be expected from the presumptive diagnosis.