The first in a series of treatment studies planned by the IC Clinical Trials Group tested the effectiveness of pentosan polysulfate sodium (Elmiron) and hydroxyzine hydrochloride (Atarax) in 121 patients with IC. Most volunteers reported experiencing moderate pain, discomfort, and urinary frequency for at least a year before entering the study.

IC is a chronic, debilitating condition that affects about a million people, most of them women. Patients suffer pelvic, bladder, or perineal pain and the urge to urinate as often as 18 times a day. Available treatments are limited and not effective for everyone. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) initiated the Clinical Trials Group in 1998 to identify useful therapies for this devitalizing and difficult disease with no known cause and no cure. The Group is also supported by the NIH Office of Research on Women's > Health.

Elmiron and Atarax were chosen for early testing because patients prefer oral drugs and each drug has different mechanisms of action. Elmiron is the only oral drug approved by the Food and Drug Administration for IC. Doctors do not know exactly how it works, but one theory is that it may repair defects in the lining of the bladder. In some patients, mast cells are present in the tissue of the bladder wall, possibly a sign of an allergic or autoimmune reaction. Atarax, an antihistamine previously untested in a randomized, placebo-controlled trial for IC, reduces mast cell activity. Mast cell activity can cause bladder inflammation and pain and may play a part in IC.

Patients in the randomized trial received either Elmiron or Atarax, a combination of the two, or a placebo. Researchers hoped that a combinati
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Contact: Mary Harris
Mary_Harris@nih.gov
301-496-3583
NIH/National Institute of Diabetes and Digestive and Kidney Diseases
14-Aug-2003