Desloratadine (Clarinex, Clarinex Reditabs) is a medication used to treat allergies and hives (chronic urticaria) in adults and children 12 years of age and older. Desloratadine (Clarinex) is an antihistamine. It works by blocking histamine, a natural chemical in your body that causes allergy symptoms. By blocking histamine, it helps relieve allergy symptoms like itchy eyes, a runny nose, sneezing, and hives. Desloratadine, sold under the brand name Aerius among others, is a tricyclic H 1 receptor inverse agonist that is used to treat allergies. It is the major active metabolite of loratadine. Desloratadine was patented in 1984 and came into medical use in 2001. [8]. Clarinex (Desloratadine) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. Find patient medical information for Desloratadine (Clarinex) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings What is Clarinex? Clarinex is a prescription medicine that contains the medicine desloratadine (an antihistamine). Clarinex is used to help control the symptoms of: seasonal allergic rhinitis (sneezing, stuffy nose, runny nose and itching of the nose) in people 2 years of age and older. Desloratadine is an antihistamine. It is used to relieve the symptoms of hay fever and hives of the skin. Antihistamines work by preventing the effects of a substance called histamine, which is produced by the body. Histamine can cause itching, sneezing, runny nose, and watery eyes. Clarinex package insert / prescribing information for healthcare professionals. Includes: indications, dosage, adverse reactions and pharmacology. Although the oral solution and the orally disintegrating tablet formulation of desloratadine may be available in the marketplace, CLARINEX® Oral Solution and CLARINEX® RediTabs® Tablets are no longer marketed. CLARINEX Tablets, Oral Solution, or RediTabs Tablets may be taken without regard to meals. Clarinex is an antihistamine that reduces the effects of the natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Clarinex is used to treat the symptoms of allergies, such as sneezing, watery eyes, itching, and runny nose.