Receptor binding data indicate that at a concentration of 2–3 ng/m L (7 nanomolar), desloratadine shows significant interaction with the human histamine H1-receptor.Desloratadine inhibited histamine release from human mast cells in vitro."In some studies we reviewed, some people actually experienced more sedation with the newer, nonsedating formulas than with the older, sedating products.Urticaria and angioedema lasting more than 6 weeks have been designated as chronic urticaria (CU).Results of a radiolabeled tissue distribution study in rats and a radioligand H1-receptor binding study in guinea pigs showed that desloratadine did not readily cross the blood brain barrier. Dosing: Oral: Children: 6-11 months: 1 mg once daily 12 months to 5 years: 1.25 mg once daily 6-11 years: 2.5 mg once daily Children /= 12 years and Adults: 5 mg once daily Supplied Syrup (Clarinex®): 0.5 mg/m L (480 m L) [bubble gum flavor] Tablet (Clarinex®): 5 mg Tablet, orally-disintegrating (Clarinex® Redi Tabs®): 5 mg [contains phenylalanine 1.75 mg/tablet] Adult (usual) Chronic idiopathic urticaria: 60 mg orally twice daily.Seasonal allergic rhinitis: 60 mg orally twice daily or 180 mg once daily.
Some antihistamines may also be helpful in reducing anxiety, inducing sleep, or at preventing or treating motion sickness.
Antihistamines are a class of agents that block histamine release from histamine-1 receptors and are used to treat the symptoms of an allergic reaction, such as edema (swelling), itch, inflammation (redness), sneezing, or a runny nose or watery eyes.
Antihistamines can be further divided into those unlikely to cause drowsiness (non-sedating antihistamines) or those likely to cause drowsiness (sedating antihistamines).
So concludes a new study published in the current issue of Journal of Allergy and Clinical Immunology in which researchers compared 18 previous trials investigating antihistamine-caused sedation levels in 1,500 people between ages 8 and 81.
Most of the studies reviewed used doses that were twice the recommended amount -- 50 milligrams -- of diphenhydramine, the active ingredient in Benadryl and other first-generation "sedating" allergy medications.