Alosetron (oral)

Alosetron is a prescription medication used for treating severe, chronic, irritable bowel syndrome (IBS) in women with diarrhea. 

• Alosetron is available under various brand names: Lotronex

Common side effects of Alosetron include:

• constipation;
• nausea; or
• pain or discomfort in the stomach or intestines.

Serious side effects of Alosetron include:

• hives,
• difficult breathing,
• swelling of the face, lips, tongue, or throat
• severe constipation, or ischemic colitis (caused by reduced blood flow to the intestines),
• new or worsening constipation;
• stomach pain;
• bright or dark red blood in your stools; or
• bloody diarrhea.

Rare side effects of Alosetron include:

• none

Seek medical care or call 911 at once if you have the following serious side effects:

• Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights.
• Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out.

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult and pediatric dosage

Tablet

• 0.5 mg
• 1 mg

Irritable Bowel Syndrome

Adult dosage

• Initial 0.5 mg orally every 12 hours for 4 weeks; if well tolerated, but inadequate control of IBS symptoms, increase up to 1 mg every 12 hours; discontinue if no improvement after 4 weeks

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first

• Alosetron has severe interactions with the following drugs:
  • apomorphine
  • fluvoxamine
• Alosetron has serious interactions with at least 28 other drugs.
• Alosetron has moderate interactions with at least 31 other drugs.
• Alosetron has minor interactions with at least 70 other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions or concerns.

Contraindications

• constipation (especially if it is your main IBS symptom);
• a history of severe or ongoing constipation;
• obstruction or perforation of your intestines;
• Crohn's disease, ulcerative colitis, or diverticulitis;
• blood clots, or circulation problems affecting your intestines;
• children younger than 18 years old
• severe liver disease; or
• a condition for which you also take fluvoxamine (Luvox).

Effects of drug abuse

• none.

Short-Term Effects

• See “What Are Side Effects Associated with Using Alosetron?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Alosetron?”

Cautions

• Alosetron should be used only by women with severe irritable bowel syndrome and diarrhea as the main symptom.
• Do not start taking alosetron if you are constipated. You also should not take alosetron if you take another medicine called fluvoxamine (Luvox).
• Serious or fatal side effects on the stomach and intestines have occurred in some people taking alosetron. In rare cases, alosetron has caused severe constipation, or ischemic colitis (caused by reduced blood flow to the intestines).
• Stop taking alosetron and call your doctor right away if you have: new or worsening constipation, stomach pain, bright or dark red blood in your stools, or bloody diarrhea. You may need to permanently discontinue this medicine if you have these side effects.
• If you stop taking alosetron for any reason, do not start taking it again without your doctor's advice.

Pregnancy and Lactation

• The available data on use in pregnant women are insufficient to conclude any drug-associated risks for major birth defects, miscarriage, or adverse maternal or fetal outcomes.

Lactation

• If you breastfeed while taking alosetron, call your doctor if your baby shows signs of constipation or has bloody stools.