The drug alosetron acts on tissue hormones from the serotonin group, which are predominantly found in the human digestive tract and here control the transport of stool through the intestine. The active ingredient is only administered in the USA under strict conditions to patients with severe irritable bowel syndrome. The reason: serious side effects are possible, which is why the drug was also taken off the market for several months.
What is alosetron?
The drug is administered only in the United States under strict conditions to patients with severe irritable bowel syndrome. The drug alosetron belongs to the setrone group, although it differs from them in terms of its effects. While setrone is commonly used during tumor chemotherapy or radiation therapy and for postoperative nausea with vomiting, alosetron is administered in the United States to treat irritable bowel syndrome. In part, it can also relieve pain in some patients suffering from fibromyalgia syndrome. Alosetron was initially approved in the U.S. in early 2000, but was temporarily withdrawn from the market after nine months due to serious side effects. In mid-2002, the drug was reintroduced to the market under the trade name Lotronex with a limited approval.
Pharmacologic effect
Alosetron is a selective inhibitor that acts on serotonin receptors. These appear particularly frequently in the human body in the gastrointestinal tract. Like all active ingredients from this group of substances, alosetron initially has an anti-vomiting effect. In addition, the drug causes stool to move more slowly through the intestinal tract. Serotonin is a tissue hormone that is mainly found in the central nervous system, the cardiovascular system and the intestinal nervous system. This hormone affects not only the activity of the gastrointestinal tract, but also blood pressure and the transmission of signals in the central nervous system. In the gastrointestinal tract, the hormone has sensory and motor functions. On the one hand, the intestine responds directly to serotonin, and on the other hand, it assumes a function as a neurotransmitter. Serotonin, which is released in the intestinal mucosa, activates various neurons. These then interact, resulting in the wave of contraction and subsequent relaxation that moves the stool through the intestine toward the anus. In its sensory function, serotonin relays discomfort from the digestive system to the brain and can cause nausea and vomiting without identifying a specific cause for this discomfort.
Medical application and use
Alosetron is administered in the United States to women who have severe irritable bowel syndrome under certain conditions. The requirements include that they have been suffering from the symptoms – primarily diarrhea – for at least six months and have not responded to other treatments. In addition, their digestive tract must not have any biochemical or anatomical abnormalities. Physicians who want to administer the preparation must enroll in a so-called prescriber register of the manufacturer and conclude a written agreement with their patient. IBS is the term used to describe various functional bowel disorders that can mimic symptoms of various other bowel diseases. Because IBS is not dangerous in itself, prolonged diarrhea is considered a leading symptom for the prescription of alosetron. The reason: because stool is too liquid during diarrhea, prolonged diarrhea can lead to a large loss of fluids and electrolytes. This is dangerous for affected patients in that electrolytes such as sodium, magnesium, calcium, or phosphate play an important role in the proper functioning of cells in the body.
Risks and side effects
About one-third of patients treated with alosetron complain of constipation. This means they are able to empty their bowels less than three times a week. Other common side effects include abdominal pain, malaise, and nausea. About two per thousand of all female patients who complain of side effects experience severe constipation, requiring surgical intervention. Ischemic bowel inflammation is also possible. This term is used to describe various inflammations in the large or small intestine, which can be acute or chronic.These are often accompanied by mucous-bloody diarrhea and, in extreme cases, can even lead to death if this side effect is not treated as soon as possible.
