Claritin and Sudafed belong to different classes of drugs. Claritin is an antihistamine and Sudafed is a decongestant. They are both used to treat allergy and hayfever symptoms such as runny nose. However, Claritin is also used to treat allergic skin reactions such as such as hives and itching in people with chronic skin reactions, whereas Sudafed is used to treat nasal and sinus congestion.

Claritin (loratadine) is an antihistamine that reduces the effect of the natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Claritin is used to treat the symptoms of seasonal allergies, such as sneezing, watery eyes, and runny nose and itching of the nose and throat. Claritin is also used to treat skin hives and itching in people with chronic skin reactions.

Sudafed (pseudoephedrine) is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose). Pseudoephedrine is used to treat nasal and sinus congestion, or congestion of the tubes that drain fluid from your inner ears, called the eustachian tubes.

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