Before taking cholestyramine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: constipation, hemorrhoids, kidney disease.Some products may contain sugar or aspartame. Caution is advised if you have diabetes, phenylketonuria (PKU), or any other condition that requires you to limit/avoid these substances in your diet. Ask your doctor or pharmacist about using this product safely.Because this drug can interfere with the absorption of certain nutrients (such as folic acid, fat-soluble vitamins including A, D, E, K), your doctor may direct you to take a multivitamin supplement. Consult your doctor for more information.Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Older adults may be more sensitive to the side effects of this drug, especially constipation.During pregnancy, this medication should be used only when clearly needed. It may affect the absorption of certain nutrients. Discuss the risks and benefits with your doctor.This medication is unlikely to pass into breast milk. However, it may affect the absorption of certain nutrients. Consult your doctor before breast-feeding.