Orally disintegrating solid. 1 LORATADINE (lor AT a deen) is an antihistamine. It helps to relieve sneezing, runny nose, and itchy, watery eyes. This medicine is used to treat the symptoms of indoor and outdoor allergies. It is also used to treat itchy skin rash and hives. This drug also comes in other forms, including Oral syrup, Oral Solution, Oral tablet. This drug can cause serious side effects.