Clarinex (Desloratadine) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. Desloratadine (Clarinex) is used to treat allergy symptoms and to relieve itching caused by hives. Learn about side effects, warnings, dosage, and more. DESCRIPTION: CLARINEX (desloratadine) Tablets are light blue, round, film coated tablets containing 5 mg desloratadine, an antihistamine, to be administered orally. Clarinex (desloratadine) provides 24‑hour relief with once‑daily dosing and minimal drowsiness for most users. It is used for seasonal/perennial allergic rhinitis and chronic hives. Medscape - Indication-specific dosing for Clarinex, Clarinex RediTabs (desloratadine), frequency-based adverse effects, comprehensive interactions, contraindications, pregnancy & lactation. 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 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. Clarinex package insert / prescribing information for healthcare professionals. Includes: indications, dosage, adverse reactions and pharmacology. Find patient medical information for Desloratadine (Clarinex) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings 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.