Irritable bowel syndrome (IBS) is a disorder of the function of the lower portion of the intestines. The cause of the syndrome evades medical experts and scientists. The aim of medical intervention is the relief of the associated symptoms. The symptoms of IBS are abdominal pain, diarrhea and constipation, or a combination of both. Treatment includes the use of anti-diarrheal medications, antibiotics, anticholinergic medications, which relieve painful bowel spasms, and antidepressants. Two new medications have been approved by the Food and Drug Administration (FDA) for the treatment of IBS. Another medication is still in the clinical trial phase.
Alosetron hydrochloride (Lotronex) was re-approved by the FDA in June 2002 for the treatment of women with severe diarrhea-predominant IBS. Clinical studies have not provided adequate results to confirm the benefits of this medication for men. Lotronex is designed to relax the colon and slow the passage of stool through the colon. Its use is indicated only for women who have not responded adequately to conventional IBS treatment. Infrequent but serious adverse side effects have been reported. Patients should discontinue use of Lotronex immediately if symptoms of ischemic colitis or constipation develop (1) The symptoms of ischemic colitis are the sudden or gradual onset of abdominal pain and tenderness or cramping in the left lower part of the abdomen. Additional symptoms are low-grade fever, bright red blood in the stool, a feeling of urgency with a bowel movement, diarrhea, nausea, and vomiting.(2)
Lubiprostone (Amitiza) has been approved for the treatment of women with severe constipation-predominant IBS who have not responded adequately to conventional IBS therapy. Female patients must be 18 years of age and older. The recommended dose for IBS treatment is 8 micrograms twice daily. Amitiza increases fluid secretion in the small intestine to assist with the passage of stool.(3)
Asimadoline is a medication which is currently in clinical development. It acts as an antagonist against receptors in the digestive tract that control pain and bowel motility. (4)
(2) www. mayoclinic. com