ALEGYSAL

Pemirolast potassium is a mast cell stabilizer that inhibits the in vivo Type I immediate hypersensitivity reaction. In vitro and in vivo studies have demonstrated that pernirolast inhibits the antigen-induced release of inflanunatory mediators (e.g., histamine, leukotriene C4, D4, E4) from human mast cells. In addition, pemirolast inhibits the chemotaxis of eosinophils into ocular tissue and blocks the release of mediators from human easinophils. Although the precise mechanism of action is unknown, the drug has been reported to prevent calcium influx into mast cells upon antigen stimulation.