The Effect of H₂ Receptor Antagonist in Acid Inhibition and Its Clinical Efficacy / 대한소화기학회지

ABSTRACT

The first histamine H₂ receptor antagonists (H₂RAs) were developed in the early 1970s. They played a dominant role in treating peptic ulcer disease and gastroesophageal reflux disease (GERD). H₂RAs block the production of acid by H⁺, K⁺-ATPase at the parietal cells and produce gastric luminal anacidity for varying periods. H₂RAs are highly selective, and they do not affect H₁ receptors. Moreover, they are not anticholinergic agents. Sequential development of H₂RAs, proton pump inhibitors (PPIs), and discovery of Helicobacter pylori infection changed the paradigm of peptic ulcer disease with marked decrease of morbidity and mortality. PPIs are known to be the most effective drugs that are currently available for suppressing gastric acid secretion. Many studies have shown its superiority over H₂RAs as a treatment for acid-related disorders, such as peptic ulcer disease, GERD, and Zollinger-Ellison syndrome. However, other studies have reported that PPIs may not be able to render stomach achlorhydric and have identified a phenomenon of increasing gastric acidity at night in individuals receiving a PPI twice daily. These nocturnal acid breakthrough episodes can be eliminated with an addition of H₂RAs at night. The effectiveness of nighttime dose of H₂RA suggests a major role of histamine in nocturnal acid secretion. H₂RAs reduce secretion of gastric acid, and each H₂RA also has specific effects. For instance, nizitidine alleviates not only symptoms of GERD, but also provokes gastric emptying, resulting in clinical symptom improvement of functional dyspepsia. The aim of this paper was to review the characteristics and role of H₂RAs and assess the future strategy and treatment of upper gastrointestinal disease, including acid related disorders.