1 What is Lotronex?

Brand: Lotronex

Generic: Alosetron (Oral Route)

Lotronex is used to treat irritable bowel syndrome (IBS) in women who have diarrhea as their main symptom. This medication is only used in severe cases of IBS that have not responded to other methods of treatment.

IBS is also known as irritable colon or spastic colon. IBS may be caused by a chemical called serotonin, which causes your intestinal system to be overactive. This medication works by blocking the action of serotonin on the intestine. This reduces the cramping abdominal pain, abdominal discomfort, bowel urgency and diarrhea caused by IBS. This medication does not cure IBS and may not help everyone who takes it.

Alosetron is available through a restricted marketing program. Only doctors enrolled in the program can write a prescription for this medication.

This product is availabale in the following forms: Tablet.

Have a question aboutIrritable Bowel Syndrome?Ask a doctor now

2 What To Know Before Using

Before using Lotronex, you must know all about the risks and complications associated with it.

As with all medicines, the risks must be compared to how much a medication will help you. This is a decision that you and your doctor will make together.

For this medication, there are many things that need to be considered:

  • AllergiesInform your doctor if you have ever had an allergic reaction to doxorubicin or to any other medications. It is also important to inform your doctor of any non-medicine allergies such as foods, dyes, preservatives or animals..
  • Pediatric: Up-to-date pediatric appropriate studies have not indicated any problems that would limit the use of this medication. Use of this medication in children is not recommended because of the risk of serious side effects.
  • Geriatric: Up-to-date studies performed have demonstrated that elderly patients may have an increased risk of serious side effects compared to younger adults. Use with caution.
  • Pregnancy: This medication is listed as Pregnancy Category B. This means that animal studies have revealed no evidence of harm to the unborn baby, however there are are no studies in pregnant women OR animal studies have showed an adverse affect to the unborn baby, but studies in pregnant women have not shown a risk to the unborn baby.
  • Breastfeeding: There are no up-to-date studies in women for determining infant risk when using this medication while breastfeeding. Weigh the potential risks with the benefits before taking this medication while breastfeeding.
  • Drug Interactions: Certain medications should not be used together. However, in certain cases, two medications may be used together, even if an interaction might occur. In these cases, your doctor may want to change your dose or take other precautions.When taking this medication, it is important that you inform your doctor if you are taking any of the medications listed below. The following interactions were selected on the basis of potential significance and are not all-inclusive.Using this medication with any of the following is not recommended. Your doctor may decide not to treat you with this medication, or change some of the other medications you take:
    • Apomorphine 
    • FluvoxamineUsing this medication with any of the following medication is not recommended, but may be unavoidable in some cases. Your doctor may make the decision not to treat you with this medication or change some of the other medications you take:
    • Cimetidine
    • Ciprofloxacin
    • Gatifloxacin
    • Norfloxacin
    • OfloxacinUsing this medication with any of the following medications may increase your risk of side effects. However, using both medications may be the best treatment for you. If both medications are prescribed together, your doctor may change the dose or how often you take one or both medications:
    • Keoconazole
  • Other Interactions: Certain medications should not be used while eating, or while eating certain foods in case of negative interactions. Using alcohol or tobacco with certain mediCations may also cause negative interactions. Talk with your doctor about the use of your medication with food, alcohol or tobacco.
  • Other Medical Problems: Pre-existing medical problems may affect the use of this medication. Be sure to tell your doctor if you have any other medical problems, especially: 
    • Blood clotting problems
    • Constipation
    • Diverticulitis (abnormal pouches in bowel that become inflamed)
    • Inflammatory bowel disease (i.e. Crohn's disease, ulcerative colitis)
    • Intestinal adhesion or stricture (bowel blockage)
    • Intestinal blood circulation problem
    • Intestinal obstruction (bowel blockage)
    • Intestinal perforation (holes in bowel)
    • Ischemic colitis (poor blood flow to bowel)
    • Liver problems
    • Thrombophlebitis (inflamed blood vessel caused by blood clot)
    • Toxic megacolon (very enlarged bowel) - Should not use in patients with these conditions.
    • Liver problems - Use with caution. May have an increased risk of serious side effects.

3 Proper Usage

To use Lotronex properly, you must follow all instructions given by your doctor.

Read the medication guide before starting alosetron for the first time and each time you refill your prescription.

Your doctor will ask you to sign a Patient-Physician Agreement after you read the medication guide. Signing the agreement means that you understand the risks and benefits of alosetron therapy and that you have read and understood the medication guide.

Only take this medication as directed by your doctor. Do not take more, less or for a longer or shorter period of time than your doctor tells you.

This medication may be taken with or without food.


Different patients will be given a different dose of this medication based on the strength of the medication. The number of doses you take each day, the time between doses and the length of time you take this medication depends on the reason you are taking this medication.

The following information only includes the average dose of this medication. If your dose is different, do not change it without first speaking to your doctor.

  • Adults - Start with 0.5mg twice a day for 4 weeks. Your doctor may increase yoru dose to 1mg twice a day for another 4 weeks.
  • Children - Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medication, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and resume your normal dosing schedule. Do not double dose.


Store this medication in a closed container at room temperature. Keep it away from heat, moisture and direct light. Do not freeze. Keep ourTof the reach of children.

Do not keep expired medication or medication you no longer need. Ask your doctor how to dispose of any medication you do not use.

4 Precautions To Take

It is very important that your doctor checks in with you often while you are receiving this medication to make sure that it is working

Stop taking this medication and inform your doctor immediately if you become constipated or experience symptoms of poor blood flow to your bowels (ischemic colitits). Some symptoms of poor blood flow are new or worsening abdominal pain, bloody diarrhea or blood in the stool.

Do not begin taking this medication again unless your doctor tells you to. Do not take other prescription or over-the-counter medications without asking your doctor, especially fluvoxamine.

5 Potential Side Effects

Make sure you meet with your doctor in using Lotronex to avoid unwanted potential side effects.

A medication may produce unwanted affects along with the intended effects. Although not all of these side-effects may occur, if they do occur, they may need medical attention.

Check with your doctor immediately if you experience any of the following side-effects:

More Common:


Get emergency help immediately if any of the following signs of overdose occur:

  • Clumsiness, unsteadiness, trembling or other problems with muscle control or coordination
  • Convulsions
  • Difficulty breathing
  • Shakiness and unsteady walk
  • Withdrawn and socially detached behaviour

Some side effects that may occur do not normally need medical attention. These may leave as your body becomes accustomed to treatment. Ask your doctor about ways to prevent or reduce some of these side effects.

Talk to your doctor if any of the following side effects continue or are bothersome, or if you have questions:

Less Common:

  • Bleeding after bowel movement
  • Full or bloated feeling
  • Pressure in the stomach
  • Swelling of abdominal or stomach area
  • Uncomfortable swelling around the rectal area

Some patients may experience other side effects that are not listed. Check with your doctor if you notice any other side effects.

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

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