The fastest way to treat stomach acid is nonexistent. The medications used to treat stomach acid include acid inhibitors, mucosal protection drugs, and antacids. 1. Acid inhibitors commonly used proton pump inhibitors (PPI) and Hâ‚‚ receptor antagonist drugs. Such as omeprazole, lansoprazole, esomeprazole, cimetidine, famotidine, ranitidine and so on. 2. Commonly used drugs for mucosal protection include bismuth potassium citrate and bismuth pectin. However, since the kidney is the main excretory organ of bismuth, bismuth should be avoided in people with renal dysfunction. 3. Commonly used antacids include magnesium aluminum carbonate, aluminum hydroxide, sodium bicarbonate, calcium carbonate and so on. If you need to use medication, it is recommended to use medication under the guidance of a doctor, not blindly self-medication to avoid adverse effects.