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 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 should be prescribed only by a qualified doctor who is enrolled in a prescribing program specific for this drug. You will be required to read and sign a Patient-Physician Agreement form before you get a prescription for alosetron.

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

What should I discuss with my healthcare provider before taking Alosetron?

Do not use alosetron if you have:

• 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
• if you are also taking fluvoxamine (Luvox) to treat obsessive-compulsive disorder

Tell your doctor if you have ever had any of the conditions listed above.

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.

FDA pregnancy category B. This medication is not expected to be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

It is not known whether alosetron passes into breast milk or if it could harm a nursing baby. Do not take alosetron without telling your doctor if you are breast-feeding a baby.

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

This medicine should not be given to a child younger than 18 years old.

Alosetron Side Effects

What are the possible side effects of Alosetron?

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 right away if you have any of these serious side effects:

• 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
• 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.

Alosetron Interactions

What other drugs affect Alosetron?

Do not take alosetron if you are also taking fluvoxamine (Luvox) to treat obsessive-compulsive disorder.

Before taking alosetron, tell your doctor if you are using any of the following drugs:

• cimetidine (Tagamet)
• ketoconazole (Nizoral), itraconazole (Sporanox), voriconazole, (VFEND)
• isoniazid (Nydrazid)
• hydralazine (BiDil)
• procainamide (Procanbid, Procan SR, Pronestyl)
• clarithromycin (Biaxin) or telithromycin (Ketek)
• HIV medicines such as tipranavir (Aptivus), indinavir (Crixivan), saquinavir (Invirase), lopinavir/ritonavir (Kaletra), fosamprenavir (Lexiva), ritonavir (Norvir), atazanavir (Reyataz), or nelfinavir (Viracept); or
• an antibiotic such as ciprofloxacin (Cipro), levofloxacin (Levaquin), moxifloxacin (Avelox), norfloxacin (Noroxin), or ofloxacin (Floxin)

This list is not complete and there may be other drugs that can interact with alosetron. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

What should I avoid while taking Alosetron?

Follow your doctor’s instructions about any restrictions on food, beverages, or activity while you are using alosetron.

Alosetron Dosage

How should I take Alosetron?

Take this medication exactly as it was prescribed for you. Do not take the medication in larger amounts, or take it for longer than recommended by your doctor. Follow the directions on your prescription label.

Take each dose with a full glass of water.

Alosetron can be taken with or without food.

Stop taking alosetron and call your doctor if you become constipated while taking alosetron.

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.

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

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.

Store alosetron at room temperature away from moisture and heat.

What happens if I overdose on Alosetron?

Seek emergency medical attention if you think you have used too much of this medicine.

Symptoms of an alosetron overdose are not known.

What happens if I miss a dose of Alosetron?

Skip the missed dose and take the medicine at the next regularly scheduled time. Do not take two doses at once, or take extra medicine to make up the missed dose.

Edited from everydayhealth.com