This drug is a second generation, tricyclic antihistamine with peripheral H1-antagonist action. Desloratadine is the active descarboethoxy metabolite of loratidine. It has a long-lasting effect and does not cause drowsiness as it does not readily enter the central nervous system. Desloratadine is used as an antihistamine to relieve allergy symptoms such as watery eyes, runny nose, itching eyes or nose, sneezing, hives, and itching. It works by blocking a certain natural substance called histamine that your body makes during an allergic reaction. This drug is recommended to take by mouth with or without food.