Alosetron (By mouth)


Alosetron (a-LOE-se-tron)

Treats irritable bowel syndrome (IBS).

Brand Name(s)


When This Medicine Should Not Be Used

How to Use This Medicine


  • Take your medicine as directed.
  • This medicine should come with a Medication Guide. Ask your pharmacist for a copy if you do not have one.
  • You may take this medicine with or without food.
  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Do not use alosetron if you are also using fluvoxamine.
  • Some medicines can affect how alosetron works. Tell your doctor if you are taking any of the following:
    • Antibiotics, such as ciprofloxacin, clarithromycin, levofloxacin, moxifloxacin, telithromycin
    • Antifungal medicine, such as itraconazole, ketoconazole, voriconazole
    • Cimetidine
    • Hydralazine
    • Isoniazid
    • Procainamide

Warnings While Using This Medicine

  • Tell your doctor if you are pregnant or breastfeeding, or if you have liver disease. Tell your doctor about all digestive problems you have now or have ever had.
  • You will be asked to sign a patient acknowledgment form before you take this medicine. The form tells you about the risks of alosetron. Make sure you understand the information on the form before you sign it. If you have any questions, ask your doctor. You should not use alosetron if you do not understand the information on the form.
  • This medicine may cause a very serious bowel disease called ischemic colitis.
  • If you develop constipation, stop taking this medicine and call your doctor. Tell your doctor if the constipation does not go away after you have stopped taking the medicine. Do not start taking the medicine again until your doctor tells you to.
  • Call your doctor if your symptoms do not improve or if they get worse.
  • Your doctor will check your progress and the effects of this medicine at regular visits. Keep all appointments.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Bleeding from your rectum
  • Constipation
  • Red or black stools
  • Stomach pain or cramps (new or worse)

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last reviewed on 8/4/2014

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