loratadine brands

Molecular formula: C22H23ClN2O2

Histamine release is a key mediator in allergic rhinitis and urticaria. As a result, loratadine exerts it's effect by targeting H1 histamine receptors. Loratadine binds to H1 histamine receptors found on the surface of epithelial cells, endothelial cells, eosinophils, neutrophils, airway cells, and vascular smooth muscle cells among others. H1 histamine receptors fall under the wider umbrella of G-protein coupled receptors, and exist in a state of equilibrium between the active and inactive forms. Histamine binding to the H1-receptor facilitates cross linking between transmembrane domains III and V, stabilizing the active form of the receptor. On the other hand, antihistamines bind to a different site on the H1 receptor favouring the inactive form. Hence, loratadine can more accurately be classified as an "inverse agonist" as opposed to a "histamine antagonist", and can prevent or reduce the severity of histamine mediated symptoms. All of the available H1 receptor antagonists are reversible, competitive inhibitors of the interaction of histamine with H1 receptors. /H1 Receptor Antagonists/ H1 antagonists inhibit most responses of smooth muscle to histamine. /H1 Antagonists Receptors/ Within the vascular tree, the H1 antagonists inhibit both the vasoconstrictor effects of histamine and, to a degree, the more rapid vasodilator effects that are mediated by H1 receptors on endothelial cells. /H1 Receptor Antagonists/ H1 antagonists strongly block the action of histamine that results in increased capillary permeability and formation of edema and wheal. /H1 Receptor Antagonists/ For more Mechanism of Action (Complete) data for LORATADINE (6 total), please visit the HSDB record page.

Source: PubChem (NCBI) · compound 3957