Alosetron

Conditions Treated

Alosetron is used to treat diarrhea, pain, cramps, and the feeling of an urgent need to have bowel movements caused by irritable bowel syndrome (IBS; a condition that causes stomach pain, bloating, constipation, and diarrhea) in women who have diarrhea as their main symptom and have not been helped by other treatments. Alosetron is in a class of medications called serotonin antagonists. Alosetron works by slowing the movement of stool (bowel movements) through the intestines.

Possible Side Effects

What Side Effects Can This Cause?

Alosetron may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• upset stomach
• hemorrhoids

Some side effects can be serious. If you experience any of the symptoms listed in the IMPORTANT WARNING section, call your doctor immediately.If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].

Usage Instructions

How Should This Medication Be Used

Alosetron comes as a tablet to take by mouth. It is usually taken twice a day with or without food. Take alosetron at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take alosetron exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor. Your doctor will probably start you on a low dose of alosetron. Your doctor will want to talk to you after you have taken the low dose for 4 weeks. If your symptoms are not controlled but you are not experiencing serious side effects of alosetron, your doctor may increase your dose. If you take the increased dose for 4 weeks and your symptoms are still not controlled, alosetron is not likely to help you. Stop taking alosetron and call your doctor. Alosetron may control IBS but will not cure it. If you and your doctor agree that you should continue to take alosetron after the initial trial period, do not stop taking alosetron without talking to your doctor. If you stop taking alosetron, your IBS symptoms may return within 1 or 2 weeks.

What Dietary Instructions Should I Follow

Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medication.

Are There Any Special Instructions

Before taking alosetron, tell your doctor and pharmacist if you are allergic to alosetron or any other medications. do not take fluvoxamine (Luvox) while you are taking alosetron. tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention the medications listed in the IMPORTANT WARNING section and amiodarone (Cordarone, Pacerone); certain antifungals such as fluconazole (Diflucan), itraconazole (Sporanox), ketoconazole (Nizoral), and voriconazole (Vfend);aprepitant (Emend); cimetidine (Tagamet); clarithromycin (Biaxin, in Prevpac);cyclosporine (Neoral, Sandimmune); diltiazem (Cardizem, Dilacor, Tiazac, others); erythromycin (E.E.S., E-Mycin, Erythrocin);fluoroquinolone antibiotics including ciprofloxacin (Cipro), gatifloxacin (Tequin), levofloxacin (Levaquin), norfloxacin (Noroxin), ofloxacin (Floxin), others;fluoxetine (Prozac, Sarafem); hormonal contraceptives (birth control pills, implants, injections, rings, and patches); hydralazine (apresoline); isoniazid (INH, Nydrazid);lovastatin (Advicor, Altocor, Mevacor);certain medications for human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) such as atazanavir (Reyataz),delaviridine (Rescriptor); efavirenz (Sustiva);indinavir (Crixivan), lopinavir (in Kaletra),nelfinavir (Viracept), ritonavir (Norvir, in Kaletra),and saquinavir (Fortovase, Invirase);nefazodone; procainamide (Procanbid, Pronestyl);sertraline (Zoloft); telithromycin (Ketek); ticlopidine (Ticlid);troleandomycin (TAO);verapamil (Calan, Covera, Isoptin, Verelan); and zafirlukast (Accolate). Many other medications may also interact with alosetron, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. tell your doctor if you have or have ever had the conditions listed in the IMPORTANT WARNING section or any stomach or bowel problems, surgery to your stomach or bowels, or liver or kidney disease.