Medications

Oral Therapy

Drugs should be considered after conservative measures have failed to provide substantial improvement in symptoms.

• Sodium pentosan polysulfate (Elmiron) is the only oral drug approved by the U.S. Food and Drug Administration (FDA) for the treatment of people with IC. Its mode of action is not entirely understood, but it may act as an antiinflammatory agent. Because it is structurally similar to naturally occurring glucosaminoglycans, it is believed to restore the protective layer on the bladder epithelium. Sodium pentosan polysulfate also has some anticoagulant action, and caution should be used when other anticoagulants are given. The dosage is 100 mg orally three times a day. Clinical studies suggest that maximal effects are not observed until the drug has been taken for at least five to six months. Side effects of sodium pentosan polysulfate include headache, rash, dizziness, diarrhea, dyspepsia, abdominal pain, hair loss (which is reversible), and liver function abnormalities.
• Tricyclic antidepressants (amitriptyline [Elavil, 25-75 mg at bedtime], doxepin [Adapin, Sinequan, 75 mg at bedtime], and imipramine [Tofranil, 25 mg three times a day]) are used in people with IC for their pain-relieving effects. They alleviate both the pain and frequency of IC and also help deal with the psychological stress associated with a chronically painful condition. They also cause drowsiness and deepen REM sleep, which helps in decreasing nocturia.
• Antihistamines can be helpful in treating IC. Hydroxyzine (Atarax, Vistaril, 25-75 mg at bedtime) and cimetidine (Tagamet, 300 mg twice daily) are the only antihistaminics that have been specifically used for the treatment of people with IC. The main side effect of hydroxyzine is sedation, which is actually a benefit because it helps the person with IC to sleep better at night and get up to urinate less frequently.
• Anticholinergics and antimuscarinics are the mainstay therapy for overactive bladder, urgency, and urge incontinence. They have a central role in IC. Tolteradine (Detrol), oxybutynin (Ditropan), and others are used extensively with good results and few side effects. High doses may be required, and combination therapy may be effective.

Bladder Drug Instillation (Bladder Wash)

• Dimethyl sulfoxide (DMSO, Rimso-50) is the only drug approved by the FDA for use in bladder instillation. Using a catheter, the bladder is filled with DMSO, which is retained in the bladder for 15-20 minutes before being emptied. The technique does not require anesthesia, hospitalization, or the use of an operating room. This treatment is given every week or two weeks for six to eight weeks. DMSO is believed to work as an antiinflammatory agent and therefore reduces pain. It may also prevent contractions that cause pain, frequency, and urgency. By the end of the sessions, complete relief of symptoms is often obtained.

If symptoms recur, more treatments can be given. People who are willing to catheterize themselves may be able to self-administer treatments at home. Side effects include a garlic-like body odor in some people. For some people, DMSO instillations can be painful. This can often be relieved by first instilling a local anesthetic into the bladder through a catheter or by mixing the local anesthetic with DMSO. Some clinicians substitute intravesical (instilled in the bladder) heparin for DMSO. Other agents can be added to DMSO making an IC "cocktail." These include corticosteroids, heparin, normal saline> (sodium chloride solution), and lidocaine.