Medications:

A number of medications are available that increase sphincter or pelvic muscle strength or relax the bladder, improving the ability to hold more urine. Medications are prescribed for all kinds of incontinence, but they are generally most helpful for urge incontinence.

Medications Used for Urge Incontinence

Anticholinergics. Anticholinergics work in the following ways:

• Inhibit the involuntary contractions of the bladder
• Increase capacity of the bladder
• Delay the initial urge to void

These drugs can produce small but significant improvements. However, the medications have not been rigorously compared with behavioral methods, such as bladder training and Kegel exercises, which are very effective for most cases of urge incontinence. Anticholinergics can have distressing side effects, notably dry mouth.

Anticholinergics include:

• Propantheline (ProBanthine). This drug used to be the most commonly prescribed anticholinergic, but has been largely replaced by newer anticholinergics with fewer side effects.
• Oxybutynin (Ditropan, Oxytrol)
• Tolterodine (Detrol)
• Hyoscyamine (Levbid, Cystospaz)
• Trospium (Sanctura)
• Darifenacin (Enablex)
• Solifenacin (Vesicare)
• Fesoterodine (Toviaz)

Extended-release versions of oxybutynin (Ditropan XL) and tolterodine (Detrol LA) are available. They improve continence and have fewer adverse effects than short-acting forms. A skin patch form of oxybutynin (Oxytrol) is another option. It may have fewer side effects, such as dry mouth and constipation, than the pill form. Oxybutynin is also approved for pediatric use in children ages 6 and older.

Side effects of anticholinergic drugs include:

• Dry eyes (a particular problem for people who wear contact lenses; patients who wear contacts may wish to start with low doses of medication and gradually build up)
• Dry mouth
• Headache
• Constipation
• Rapid heart rate
• Confusion, forgetfulness, and possible worsening of mental function, particularly in older people with dementia, such as those with Alzheimer's disease
• Hallucinations, possibly, especially for children and older adults; doctors should monitor patients for this symptom

Alpha-Blockers. Alpha-blockers are drugs that relax smooth muscles and improve urine flow. They are useful for men with benign prostatic hyperplasia who also have urge incontinence. The older alpha-blockers terazosin (Hytrin) and doxazosin (Cardura) are now prescribed less often than the newer selective alpha-blockers tamsulosin (Flomax), alfuzosin (Uroxatral), and silodosin (Rapaflo). Alpha-blockers are sometimes combined with anticholinergics to treat men with moderate-to-severe lower urinary tract symptoms, including overactive bladder.

Medications Used for Stress Incontinence

Alpha-Adrenergic Agonists. Alpha-adrenergic agonists, such as clonidine (Catapres), are used to strengthen the smooth muscle that opens and closes the internal sphincter. These drugs include ephedrine and pseudoephedrine, which have been common ingredients in numerous over-the-counter decongestants and appetite suppressants.

Such drugs may be helpful for select patients with mild stress incontinence not caused by nerve damage, but evidence on their benefits is weak. They also can have significant side effects, including agitation, insomnia, and anxiety. Alpha-adrenergic agonists may have adverse effects on the heart in people with existing heart problems. People with glaucoma, diabetes, hyperthyroidism, heart disease, or high blood pressure should not take these drugs.

Antidepressants

Evidence indicates that both urge and stress incontinence are affected, in part, by central nervous system processes. Investigators are particularly interested in serotonin, norepinephrine, and noradrenaline, which are chemical messengers (neurotransmitters) that affect pathways involved with urination. (These neurotransmitters are also important for many other emotional and physical functions.) Antidepressants targeting one or both of these neurotransmitters are sometimes used for urge incontinence and may also be helpful for some people with stress incontinence.

• Tricyclic Antidepressants. Tricyclic antidepressants, such as imipramine (Tofranil), may help both urge and stress incontinence. They act as anticholinergic drugs and relax the bladder. They also strengthen the internal sphincter. These drugs should be used carefully. They pose some risk for adverse effects on the heart and possibly the lungs, and they have other severe side effects in older adults. These antidepressants produce side effects similar to anticholinergic drugs, and may cause drowsiness. They may also cause overflow incontinence in some people.
• Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs). SNRIs are specially designed antidepressants that are similar to tricyclics but do not have the same side effects. They target the neurotransmitters serotonin and norepinephrine, which are thought to play key roles in the normal action of bladder muscles and nerves. Increased neurotransmitter activity stimulates the nerve that controls the urethral sphincter. The SNRI duloxetine (Cymbalta) is approved in Europe for treatment of stress urinary incontinence. It is approved in the U.S. for other conditions, but not for stress urinary incontinence. Nevertheless, it is sometimes prescribed off-label for stress urinary incontinence. The FDA is investigating whether duloxetine can increase the risk for suicidal behavior.

Investigational Drugs

Botulinum (Botox). Botulinum, the deadly toxin that sometimes contaminates improperly cooked foods, is also a powerful muscle-relaxant. Researchers are investigating whether tiny injected amounts of a purified form (Botox) can relax the muscles and help control overactive bladder that causes urge incontinence.