Allergocrom Mechanism of Action

Pharmacology: Antiallergic eye drops. Cromolyn sodium stabilizes membranes of mast cells after they have been exposed to antigens and thus, prevents degranulation and with this the release of various chemical mediators. The mediators are biologically active molecules. They are either preformed and stored in the mast cells (ie, histamine, kinins) and mediate type I immediate allergic reactions through their release, or they are synthesized after provocative stimulation (ie, prostaglandins, leukotrienes) and mediate late type IV inflammatory reactions. Beside other mechanisms of action, cromolyn possesses calcium antagonist features. Cromolyn blocks the IgE-receptor linked calcium channel and therefore, blocks the flow of calcium into the cell normally occurring after IgE-binding. As a result, mast cell degranulation is suppressed and histamine release is avoided. Cromolyn sodium is effective in prophylaxis and therapy of an allergic reaction of the eye.
After single topical eye application to rabbits, cromolyn was shown to be present in aqueous humor for at least 7 hrs; 24 hrs after application, no remaining drug was found in the eye. Due to its very low lipid solubility, cromolyn sodium has almost no systemic absorption (in humans approximately 0.03%, in rabbits approximately 0.02%). This explains the lack of systemic side effects.