What Are the Most Common Loperamide Side Effects?

Loperamide side effects are usually mild and do not prevent the patient from successfully using the medication, although more serious side effects are possible. Some of the most frequently reported side effects include worsening diarrhea, abdominal bloating, or constipation. In some cases, more serious loperamide side effects may develop, including blistered or peeling skin, chest pain, or difficulty breathing. A severe and potentially life-threatening allergic reaction may occasionally occur as a result of taking this medication. Any questions or concerns about individualized loperamide side effects should be discussed with a doctor or other medical professional.

Gastrointestinal disturbances are among the most common loperamide side effects. Mild to moderate abdominal cramping and bloating may occur when taking this medication. Constipation may also occur, especially if too much of this drug is taken. In some cases, diarrhea may become worse instead of better or may contain blood. Any severe or persistent diarrhea, especially if accompanied by signs of dehydration, should be reported to a doctor.

Dizziness or drowsiness are possible loperamide side effects. These symptoms are usually mild and may go away once the body adjusts to the medication. Mild itching or the development of a mild skin rash are relatively common, although the presence of hives may indicate the beginning stages of an allergic reaction to the medication. If the skin begins to blister or peel, a doctor should be consulted for further evaluation.

Some patients may experience flu-like symptoms when taking loperamide. This may include a headache, runny nose, or sore throat. A mild fever may develop in some cases and does not normally present a problem. If the fever becomes high or if the accompanying symptoms become particularly bothersome, a doctor should be notified. A decreased ability to urinate or severe abdominal pain should be reported right away, as these symptoms could indicate the presence of serious complications.

Rarely, a severe and potentially life-threatening allergic reaction known as anaphylaxis may occur as a result of using this medication. This type of allergic reaction may occur suddenly or after successfully taking this medication in the past. Symptoms of anaphylaxis may include a rash, facial swelling, or difficulty breathing and should be treated as a medical emergency. Swelling of the throat can significantly impair the ability to breathe, and a lack of oxygen can result in permanent brain damage or even death after just a few minutes if not properly treated.