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- What is alosetron, and how does it work (mechanism of action)?
- What brand names are available for alosetron?
- Is alosetron available as a generic drug?
- Do I need a prescription for alosetron?
- What are the side effects of alosetron?
- What is the dosage for alosetron?
- Is alosetron safe to take if I'm pregnant or breastfeeding?
- What else should I know about alosetron?
What is alosetron, and how does it work (mechanism of action)?
Alosetron is used to treat diarrhea and abdominal discomfort that occurs in some women with irritable bowel syndrome (IBS). It works in a similar fashion as granisetron (Kytril), ondansetron (Zofran) and dolasetron (Anzemet) that are used for preventing nausea and vomiting. The discomfort and diarrhea of IBS is believed to be due to abnormal activity of the muscles of the intestines and/or the nerves that control the muscles. One of the chemical messengers which is important in coordinating the activity of intestinal nerves is serotonin. (Chemical messengers are chemicals produced and released by nerve cells that and cause changes in the activity of other nerve cells.) Alosetron belongs to a class of drugs that block one type of serotonin receptor called the 5-HT3 receptor. Serotonin and its receptors in the intestines may control pain sensation, contraction of intestinal muscle, and release of fluid into the intestines. These actions of serotonin can result in pain and diarrhea. The exact cause of IBS is unknown, but it is thought that stimuli such as food, medications, hormonal changes, or stress may trigger an excessive release or excessive response to serotonin. This may cause pain, and diarrhea seen in patients with diarrhea-predominant IBS. Alosetron, by blocking 5-HT3 receptors, reduces the actions of serotonin. Alosetron (Lotronex) was approved for marketing by the FDA in February, 2000 but was withdrawn from the market in November 2000, because of serious, life-threatening, gastrointestinal side effects. In June 2002, it was approved again by the FDA for marketing but in a restricted manner as part of a drug company-sponsored program for managing the risks associated with treatment. Use of alosetron is allowed only among women with severe, diarrhea-predominant IBS who have failed to respond to conventional treatment for IBS.
What are the side effects of alosetron?
The most common side effect with alosetron is constipation. One-quarter to one-third of patients may develop this side effect. Severe constipation or intestinal inflammation caused by poor circulation of blood (ischemic colitis) are rare but life-threatening, may require surgery, and may cause death. Therefore, alosetron must be discontinued immediately, and immediate medical attention should be sought if constipation or the signs of ischemic colitis (rectal bleeding or a sudden worsening of abdominal pain) occur.
Other important but less common side effects include:
Quick GuideIBS - Irritable Bowel Syndrome: Symptoms, Diet, Treatment
What is the dosage for alosetron?
The starting dose is 0.5 mg twice daily. If constipation develops at this dose alosetron should be discontinued until the constipation resolves. It may be restarted at 0.5 mg once daily. If 0.5 mg once daily causes constipation, then alosetron should be discontinued. After 4 weeks, patients whose symptoms are not adequately controlled may receive up to 1 mg twice daily. Patients without adequate control after 4 weeks of treatment with 1 mg twice daily should discontinue alosetron. Alosetron may be taken with or without food.
Is alosetron safe to take if I'm pregnant or breastfeeding?
It is not known if alosetron is excreted in breast milk. Therefore, it should be used cautiously by nursing mothers.
What else should I know about alosetron?
What preparations of alosetron are available?
Tablet: 0.5 and 1 mg.
How should I keep alosetron stored?
Tablets should be stored at room temperature, 15 C to 30 C (59 F to 86 F).
Reference: FDA Prescribing Information
Alosetron (Lotronex) is a drug prescribed for the treatment of severe-predominant IBS among women who suffer from chronic IBS symptoms lasting longer than 6 months, and have not responded to conventional IBS treatment. Side effects, drug interactions, dosage, and pregnancy safety information should be reviewed prior to taking this drug.
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IBS SlideshowWhat is irritable bowel syndrome (IBS)? Learn about symptoms, causes, and foods that trigger IBS. Get lifestyle tips for managing IBS through diet and with IBS medications.
IBS vs IBD Differences and Similarities
IBS (irritable bowel syndrome) and IBD (inflammatory bowel disease) are both problems with the digestive tract (gastrointestinal or GI tract), but they are not the same disease. IBS is a functional disorder (a problem with the way the GI tract functions), and IBD is a disease that causes chronic prolonged inflammation of the GI tract, that can lead to ulcers and other problems that may require surgery. The most common forms of IBD are Crohn's disease and ulcerative colitis, or UC.
Researchers do not know the exact cause of either disease, but they believe that IBS may be caused and triggered by a variety of factors (foods, stress, and the nervous system of the GI tract), while IBD may be genetic or due a problem with the immune system.
Common symptoms of both diseases are an urgent need to have a bowel movement, diarrhea, nausea, vomiting, and abdominal pain and cramping.
There are differences between the signs and symptoms of irritable bowel syndrome and inflammatory bowel disease, for example, symptoms unique to IBD are:
- Joint pain or soreness
- Skin changes
- Rectal bleeding
- Eye redness or pain
- Unintentional weight loss
- Feeling tired
Symptoms unique to irritable bowel syndrome include:
- Sexual problems
- Abdominal bloating
- Whitish mucous in the stool
- Changes in bowel movements and in the way stools look
- An urgent need to urinate
- Urinating frequently
Treatment for IBS is with diet recommendations from a doctor or nutritionist, medication, and lifestyle changes like stress management and avoiding foods that trigger the condition. Treatments for IBD depend upon the type of disease, its symptoms, and health of the patient. Surgery may be necessary for some individuals.
Brown, AC, et al. "Existing Dietary Guidelines for Crohn's Disease and Ulcerative Colitis." Medscape.
Lehrer, J. "Irritable Bowel Syndrome." Medscape. Updated: Apr 04, 2017.
Rowe, W. "Inflammatory Bowel Disease." Medscape. Updated: Jun 17, 2016.
Romanowski, A, MS, RD. "Matching the Right Diet to the Right Patient." Medscape. Jan 27, 2017.
IBS-D Irrititable Bowel Syndrome with Diarrhea
IBS-D or irritable bowel syndrome with diarrhea refers to IBS with diarrhea. Symptoms of IBS-D include
- intestinal gas (flatulence),
- loose stools,
- frequent stools,
- abdominal pain,
- diarrhea, and
New non-FDA approved IBS tests may help diagnose IBS and IBS-D. Treatment of IBS-D is geared to toward managing symptoms with diet, medication, and lifestyle changes.
Irritable Bowel Syndrome (IBS)
Irritable bowel syndrome (IBS) is a GI (gastrointestinal) disorder with signs and symptoms of:
- Abdominal pain
- Increased gas (flatulence)
- Abdominal cramping
- Food intolerance
Two new tests are now available that may help diagnose irritable bowel syndrome with diarrhea and constipation (IBS-M) and irritable bowel syndrome with diarrhea (IBS-D). Treatment for IBS includes diet changes, medications, and other lifestyle changes to manage symptoms.
Irritable Bowel Syndrome (IBS) Triggers, Prevention
Irritable bowel syndrome (IBS) is a functional disease that can affect the quality of those who suffer from this condition. People with IBS can make lifestyle changes that may modify or control the number and severity of episodes. Certain foods, medications, and hormone levels may trigger IBS episodes, for example:
- Fatty foods
- Dairy products
- Eating foods in large quantities
- Foods that contain high levels of sorbitol
- Foods that produce intestinal gas (broccoli, onions, cabbage, and beans)
- Physiological stress
- Some antibiotics
- Some antidepressants
- Medicine with sorbitol
- Menstrual pain
Exercise, diet, and other lifestyle changes can decrease IBS flares, and prevent the number and severity of IBS episodes of diarrhea and constipation.