Anatomical Therapeutic Chemical Classification System
Azelastine, a phthalazinone derivative is classified as a potent long-acting anti-allergic compound with selective H1 antagonist properties. An additional anti-inflammatory effect could be detected after topical ocular administration. Data from in vivo (pre-clinical) and in vitro studies show that azelastine inhibits the synthesis or release of the chemical mediators known to be involved in early and late stage allergic reactions e.g. leukotriene, histamine, PAF and serotonin.
Sodium cromoglicate (Cromoglicic acid) inhibits the activation of many of the cell types involved in the development and progression of asthma. Thus, sodium cromoglicate inhibits the release of inflammatory mediators including cytokines from mast cells and reduces the chemotactic activity of eosinophils and neutrophils.
Levocabastine is a potent, fast-acting and highly selective histamine H1-antagonist with a sustained duration of action.
Olopatadine is a potent selective antiallergic/antihistaminic agent that exerts its effects through multiple distinct mechanisms of action.