Antacids (Mylanta®, Rolaids®) neutralize existing stomach acid through basic chemical reaction. Bismuth subsalicylate (Pepto-Bismol®) coats the esophagus and acts as a barrier to refluxed gastric acid contents.

H2 blockers (TagametHB®, Zantac75®) partially block production of acid in stomach cells by inhibiting the action of histamine, a substance that stimulates the secretion of stomach acid.

*Mylanta® is a registered trademark of Johnson & Johnson-Merck Consumer Pharmaceuticals Co. Rolaids® is a registered trademark of McNEIL-PPC, Inc. Pepto-Bismol® is a registered trademark of Procter & Gamble. Tagamet HB® is a registered trademark of GlaxoSmithKline, Inc. Zantac 75® is a registered trademark of Boehringer Ingelheim Pharmaceuticals, Inc.