Generic Zelnorm

Tegaserod is an oral medication for the treatment of constipation and constipation-predominant irritable bowel syndrome (IBS) in women. IBS is a chronic gastrointestinal disorder characterized by recurrent abdominal pain or discomfort and altered bowel function which may be either constipation or diarrhea. As many as 20% of American adults may suffer from IBS.

Contractions of the intestinal muscles, primarily those of the colon, control the movement of food through the intestine. In constipated patients, there are fewer contractions than in persons without constipation. An important factor that controls the contractions is serotonin. Serotonin is a chemical manufactured by nerves in the intestine. It is released by the nerves and then travels and binds to receptors on the surface of nearby nerves. It is a "neurotransmitter," a chemical messenger, that is, a chemical that nerves use to communicate with each other. When it binds to receptors on the nerves that control contractions of the intestinal muscles, serotonin can either promote or prevent contractions depending on the type of receptor it binds to. Binding to some types of receptors causes contractions, and binding to other types of receptors blocks contractions.

The serotonin 5-HT4 receptor is a receptor that prevents contractions when serotonin binds to it. Tegaserod blocks the 5-HT4 receptor and prevents serotonin from binding to it. As a result, contractions increase. The increased contractions speed the transit of digesting food and reverse the constipation. In addition, tegaserod reduces the sensitivity of the intestinal pain-sensing nerves and can thereby reduce the perception of pain. Tegaserod was approved by the FDA in July, 2002.

The usual dose of tegaserod is 6 mg twice daily, most frequently for 4 to 12 weeks. Tegaserod can be taken with or without food. Older persons do not require lower doses than younger persons.

Tegaserod is well tolerated in most patients. The most commonly reported side effects are headache (1 in 6 patients), abdominal pain (1 in 8), and diarrhea (1 in 11). Only diarrhea has been reported substantially more frequently than with placebo treatment (sugar pill). Rarely the diarrhea is severe, leading to hospitalization for dehydration and requiring intravenous fluids. Ischemic colitis has been seen rarely in patients taking tegaserod although it is not clear if there is a causal relationship. Patients who develop signs of ischemic colitis--worsening abdominal pain, bloody diarrhea--should stop taking tegaserod and contact their physicians.

Tegaserod is used for the short-term treatment of women with IBS whose primary bowel symptom is constipation. It also is approved for the treatment of chronic, idiopathic constipation in men and women less than 65 years of age.