Prescription loperamide is used to control acute diarrhea. Loperamide is a type of medication classified as antidiarrheal agents. It works by decreasing the flow of fluids and electrolytes into the bowel and by slowing down the movement of the bowel to decrease the number of bowel movements.
Loperamide may cause serious or life-threatening changes in your heart rhythm, especially in people who have taken more than the recommended amount. Tell your doctor if you have or have ever had a prolonged QT interval (a rare heart problem that may cause irregular heartbeat, fainting, or sudden death), a slow or irregular heartbeat, or a low level of potassium in your blood. Also tell your doctor if you are taking or plan to take any of the following medications: amiodarone (Nexterone, Pacerone), chlorpromazine, haloperidol (Haldol), methadone (Dolophine, Methadose), moxifloxacin (Avelox), pentamidine (Nebupent, Pentam), procainamide, quinidine (in Nuedexta), sotalol (Betapace, Betapace AF), thioridazine, and ziprasidone (Geodon). Your doctor will probably tell you not to take loperamide if you are taking any of these medications or if you have any of these conditions. If you experience any of the following symptoms while taking loperamide, call your doctor immediately or instruct a friend or caregiver to call local emergency services at 911: fast, irregular, or pounding heartbeat; dizziness; lightheadedness; unresponsiveness; or fainting.
Taking more than the recommended amount of loperamide can cause heart problems that may be serious or cause death. Do not take a larger dose, take it more often, or take it for a longer period of time than prescribed by your doctor or as stated on the package.
Loperamide should not be given to a child younger than 2 years of age because of the risk of serious breathing and heart problems.
Loperamide comes as a tablet, capsule, and as a suspension or solution (liquid) to take by mouth. Prescription loperamide is sometimes taken on a schedule (one or more times a day). Follow the directions on the package or on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take loperamide exactly as directed.
Loperamide may cause side effects. Tell your doctor if you experience severe constipation or fatigue that won’t go away.
If you or someone taking loperamide experience any of the following symptoms, call your doctor immediately or get emergency medical treatment: rash, red, peeling or blistering skin, hives, itching, wheezing, difficulty breathing, fever, stomach pain or swelling, or bloody stools.
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 (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).