Loratadine is used to temporarily relieve the symptoms of hay fever (allergy to pollen, dust, or other substances in the air) and other allergies. These symptoms include sneezing, runny nose, and itchy eyes, nose, or throat. Loratadine is also used to treat itching and redness caused by hives. However, loratadine does not prevent hives or other allergic skin reactions. Loratadine is in a class of medications called antihistamines. It works by blocking the action of histamine, a substance in the body that causes allergic symptoms. Loratadine is also available in combination with pseudoephedrine (Sudafed, others). This monograph only includes information about the use of loratadine alone. If you are taking the loratadine and pseudoephedrine combination product, read the information on the package label or ask your doctor or pharmacist for more information.