History and Pharmacological Mechanism of Gastric Acid-suppressive Drugs

Gastric acid-related disorders are commonly encountered in clinical practice. Acetylcholine, gastrin, and histamine are physiological agonists that stimulate acid secretion from parietal cells. Histamine plays a decisive role in the transformation of parietal cells into acid-secreting forms. The H+, K+- ATPase proton pump, which represents the final step of acid secretion, translocates from cytoplasmic tubulovesicles to secretory canaliculi upon parietal cell stimulation and facilitates exchange of intracellular H+ with extracellular K+ in a 1:1 ratio. Histamine-2 receptor antagonists and proton pump inhibitors (PPIs) are widely used in clinical practice, and potassium-competitive acid blockers (P-CABs) have gained attention in recent times. P-CABs address the unmet needs of patients who receive conventional PPIs and have broadened the spectrum of drug choices; however, further research is warranted to confirm long-term safety of these drugs. Comprehensive understanding of the mechanisms of actions, characteristics, advantages and disadvantages, and the adverse effect profile is essential for appropriate prescription of gastric acid-suppressive drugs. In this review, we provide a developing history and outline the pharmacological mechanisms underlying various gastric acid-suppressive drugs used in clinical settings.