H2 receptor antagonists are drugs that block histamine from binding to H2 receptors on the parietal cells of the stomach lining, thus decreasing acid secretion. Commonly used H2 blockers include Cimetidine, Ranitidine, Famotidine, and Nizatidine. While generally well-tolerated, these medications can have adverse effects and interactions that are important in the context of toxicology.
