Brand Names: Lotronex

Generic Name: alosetron (oral) (Pronunciation: a LO ze tron)

• What is alosetron (Lotronex)?
• What are the possible side effects of alosetron (Lotronex)?
• What is the most important information I should know about alosetron (Lotronex)?
• What should I discuss with my healthcare provider before taking alosetron (Lotronex)?
• How should I take alosetron (Lotronex)?
• What happens if I miss a dose (Lotronex)?
• What happens if I overdose (Lotronex)?
• What should I avoid while taking alosetron (Lotronex)?
• What other drugs will affect alosetron (Lotronex)?
• Where can I get more information?

What is alosetron (Lotronex)?

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 who have had diarrhea as the main symptom for at least 6 months. Alosetron should be used only in women who have tried other IBS treatments without success. Alosetron has not been shown to be effective in men with IBS.

Alosetron is available only under a special program called the Prometheus Prescribing Program. You must be registered in the program and sign documents stating that you understand the risks and benefits of taking this medication.

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

Lotrenex 1 mg

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What are the possible side effects of alosetron (Lotronex)?

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

Stop taking alosetron and call your doctor at once if you have a serious side effect such as:

• new or worsening stomach pain;
• bleeding from your rectum or blood in your stools; or
• fast or uneven heartbeats.

Less serious side effects may include:

• mild stomach discomfort, bloating, or nausea;
• mild constipation;
• burping with heartburn;
• rectal hemorrhoids;
• bloating or gas;
• headache; or
• skin rash.

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.

Read the Lotronex (alosetron hydrochloride) Side Effects Center for a complete guide to possible side effects »

What is the most important information I should know about alosetron (Lotronex)?

Alosetron is available only under a special program called the Prometheus Prescribing Program. You must be registered in the program and sign documents stating that you understand the risks and benefits of taking this medication.

Do not start taking alosetron if you are constipated. If you have constipation while taking alosetron, stop taking the medication and call your doctor right away.

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, bloody diarrhea, or blood in your stools (bowel movements). If constipation does not improve or if it gets worse, do not start taking alosetron again until you talk to your doctor.

Alosetron does not improve the symptoms of IBS for everyone. When alosetron does work well, it helps reduce stomach pain and discomfort, bowel urgency, and diarrhea. Some or all symptoms may improve within one to two weeks of treatment.

Stop taking alosetron if your IBS symptoms do not improve after 4 weeks of treatment. If you stop taking alosetron, do not start taking it again without your doctor's advice.