How do proton pump inhibitors work and what are their long-term risks?

Proton pump inhibitors, or PPIs, like omeprazole, pantoprazole, and esomeprazole irreversibly block the hydrogen-potassium ATPase pump in gastric parietal cells, reducing stomach acid secretion by up to 90 percent. They treat gastroesophageal reflux disease, peptic ulcers, and Helicobacter pylori infection as part of combination therapy. Long-term risks include increased fracture risk from impaired calcium absorption, hypomagnesemia, vitamin B12 deficiency, Clostridioides difficile infection, and chronic kidney disease.