Alosetron

Generic name: alosetron (oral) [ a-LO-ze-tron ]
Brand name: Lotronex
Dosage form: oral tablet (0.5 mg; 1 mg)
Drug class: Serotoninergic neuroenteric modulators

Medically reviewed by Drugs.com on May 1, 2023. Written by Cerner Multum.

What is alosetron?

Alosetron blocks the action of a chemical called serotonin in the intestines. This slows the movement of stools (bowel movements) through the intestines.

Alosetron is used to treat severe, chronic irritable bowel syndrome (IBS) in women with diarrhea as the main symptom for at least 6 months. Alosetron is given after other treatments have failed.

Alosetron is not a cure for irritable bowel syndrome. After you stop taking alosetron, your symptoms may return within 1 week.

Alosetron has not been shown to be effective in men with IBS.

Alosetron may also be used for purposes not listed in this medication guide.

Alosetron side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

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 develop:

• new or worsening constipation;

• stomach pain;

• bright or dark red blood in your stools; or

• bloody diarrhea.

You may need to permanently discontinue alosetron if you have these side effects.

Older adults and those who are ill or debilitated may be more likely to have serious complications from constipation.

Common side effects of alosetron may include:

• constipation;

• nausea; or

• pain or discomfort in your stomach or intestines.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

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 alosetron 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.

Before taking this medicine

Do not take alosetron if you have ever had any of the following conditions:

• 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;

• severe liver disease; or

• a condition for which you also take fluvoxamine (Luvox).

Tell your doctor if you are pregnant or breastfeeding.

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

Alosetron is not approved for use by anyone younger than 18 years old.

How should I take alosetron?

Do not start taking alosetron if you are constipated. Stop taking the medicine and call your doctor if you become constipated.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

You may take alosetron with or without food.

Alosetron does not improve the symptoms of IBS for everyone. alosetron can help reduce stomach pain and discomfort, bowel urgency, and diarrhea. Some or all symptoms may improve within 1 to 2 weeks of treatment.

Stop taking alosetron and call your doctor if your IBS symptoms do not improve after 4 weeks of treatment.

If you stop taking alosetron for any reason, do not start taking it again without your doctor's advice.

Store at room temperature away from moisture, heat, and light.

Alosetron dosing information

Usual Adult Dose for Irritable Bowel Syndrome:

Initial dose: 0.5 mg orally twice a day
Maintenance dose: 0.5 mg orally once or twice a day; may be increased up to 1 mg orally twice a day after 4 weeks of treatment.
Maximum dose: 2 mg/day

Comment: Due to the serious gastrointestinal adverse reactions associated with this drug, treatment should be restricted to female patients for whom the benefit-to-risk balance is most favorable.

Use: Women with severe diarrhea-predominant irritable bowel syndrome (IBS) who have chronic IBS symptoms (generally lasting 6 months or longer), had anatomic or biochemical abnormalities of the gastrointestinal tract excluded, and have not responded adequately to conventional therapy

What happens if I miss a dose?

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking alosetron?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect alosetron?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can affect alosetron, and some drugs should not be used at the same time. Tell your doctor about all your current medicines and any medicine you start or stop using. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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