Pemirolast

**Semantic type:** Pharmacologic Substance

**Definition:** A pyrimidinone derivative with anti-allergic activity. Pemirolast blocks the antigen-mediated calcium ion influx into mast cells. This prevents mast cell degranulation, resulting in mast cell stabilization and inhibition of the release of inflammatory mediators, such as histamine and leukotrienes, which are involved in the allergic process. Pemirolast also prevents inflammatory mediator release from eosinophils.

**Synonyms:** - 4H-Pyrido(1,2-a)Pyrimidin-4-One, 9-Methyl-3-(1H-Tetrazol-5-yl)- - PEMIROLAST