Serious heart problems have been reported in patients who have taken too much loperamide, the active ingredient in this medicine. If you are taking any other medicines, especially Ritonavir (used to treat HIV), Quinidine (used to treat abnormal heart rhythms or malaria), Oral desmopressin (used to treat excess urination), Itraconazole or ketoconazole (used to treat fungal infections), or Gemfibrozil (used to treat high cholesterol), you should inform your doctor or pharmacist. If you are pregnant, think you may be pregnant or are planning to have a baby, or are breastfeeding, you should ask your doctor or pharmacist for advice before taking this medicine.