Clarityn Rapide Allergy Tablets Clarityn Rapide Allergy Tablets relieve the symptoms associated with allergic rhinitis (for example, hay fever), such as sneezing, runny or itchy nose, & burning or itchy eyes & may also be used to help relieve symptoms of urticaria (itching & redness), which is often known as hives or nettle rash. Clarityn Rapide Allergy Tablets contains loratadine, which is a antihistamine that reduces allergic symptoms by preventing the effects of a substance called histamine, which is produced in the body. Clarityn Rapide Allergy Tablets melt in the mouth, making them easy to take.