Zelnorm

Zelnorm 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. Zelnorm 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, zelnorm reduces the sensitivity of the intestinal pain-sensing nerves and can thereby reduce the perception of pain.