Promethazine functions on histamine-1 (H1) receptors. H1 receptors are present inside the bronchial tubes and inside the circulatory system. The attachment of histamine to those receptors results in bronchoconstriction and increased vascular permeability, which leads to plasma leakage. Excipients in commercially accessible drug preparations could possibly have clinically important out... https://billl776ibt7.wikilinksnews.com/user