This antihistamine drug is used to treat the symptoms that are associated with seasonal allergies. Some of these symptoms do include runny nose, sneezing, itching or watery eyes, and itching of the nose and throat to name some of the symptoms. Since it is an antihistamine, what this drug does is to, block a substance in the body that is responsible for causing allergic symptoms. This substance is no other than something called histamine. Loratadine is something that is marketed under different brand names. Some of these brand names do include Claritin and Shionogi in Japan. There is also a version of it called Claritin-D or Clarinex. In this version, loratadine has been combined with an ingredient called pseudoephedrine, which is a decongestant. This combination makes the product useful for colds, as well as, for the treatment of allergies. Loratadine is a drug used in the treatment of allergic symptoms - such as sneezing, itch, watery eyes, and runny nose. Loratadine may also be used to treat skin hives and skin reactions. Loratadine is used because it belongs to the antihistamine class of medicines. As an antihistamine, loratadine works to reduce histamine release from mast cells and basophils - as it's histamine that causes allergic and cold-like symptoms. More specifically, loratadine blocks the H1 receptor subtype. Loratadine is associated with its own range of potential side effects. Among these include headache, fatigue, stomach pain, vomiting, dry mouth, and feeling nervous. Some patients may also experience severe headache or altered heart rhythm.