Proton-pump inhibitor

Proton-pump inhibitors (PPIs) are a class of medications that cause a profound and prolonged reduction of stomach acid production. They do so by irreversibly inhibiting the stomach's H⁺/K⁺ ATPase proton pump. The body eventually synthesizes new proton pumps to replace the irreversibly inhibited ones, a process driven by normal cellular turnover, which gradually restores acid production.

Proton-pump inhibitors have largely superseded the H₂-receptor antagonists, a group of medications with similar effects but a different mode of action, and heavy use of antacids. A potassium-competitive acid blocker (PCAB) revaprazan was marketed in Korea as an alternative to a PPI. A newer PCAB vonoprazan with a faster and longer lasting action than revaprazan, and PPIs has been marketed in Japan (2013), Russia (2021), and the US (2023).

PPIs are among the most widely sold medications in the world. The class of proton-pump inhibitor medications is on the World Health Organization's List of Essential Medicines. Omeprazole is the specific listed example.