Real Help for Irritable Bowel Syndrome
So far, extensive research has revealed no worrisome side effects with the drug. The most common problems have been headache and nausea. "There was a two-fold increase in diarrhea in about 6% of those taking Zelnorm, but it resolved by itself, did not cause dehydration, and most patients were able to continue in the study," says Lefkowitz. Even so, he cautions that anyone whose IBS symptoms include diarrhea should not take the drug.
Zelnorm is currently under FDA review with approval expected by summer, says Lefkowitz.
Help is also on the way for those suffering mainly with diarrhea. A new drug, cilansetron, is now in the final stages of clinical trial, and approval is right around the corner, says IBS researcher Michael Camilleri, MD, professor of medicine and physiology at the Mayo Clinic in Rochester, Minn. This drug falls into the same serotonin-inhibiting class as the now-defunct drug Lotronex, he says.
And in other drug development, researchers are trying to modulate the pain-messaging pathway, and a compound known only as substance P in particular. "P stands for pain," says Camilleri, "and the theory is that in IBS, something has gone wrong with the transmission of pain signals from the gut to the brain." These new compounds will try to short-circuit those faulty signals, he explains.
Even with these promising new drugs on the horizon, there will likely be "some IBS patients who do not respond to any available treatment," says researcher Francis Creed, MD, of Manchester University in England. "About 50% of them have depression or anxiety in addition to their IBS symptoms."
Creed's team looked specifically at this hardest-to-treat group, randomly assigning them to receive eight weeks of standard medical treatment from a gastroenterologist, eight weeks of Prozac, or eight weeks of one-on-one psychotherapy session. They followed the patients for a full year after treatment.
Overall, psychotherapy was more effective than Prozac, and Prozac was more effective than standard medical treatment at improving overall quality of life. Interestingly, although the one-on-one counseling was most expensive in the short term, it was least expensive in the long term, due to fewer doctor visits, drug prescriptions, and lost work time, says Creed.