a histamine blocker and antacid (trade name Zantac) used to treat peptic ulcers and gastritis and esophageal reflux

Ranitidine (INN) (IPA: ) is a histamine H2-receptor antagonist that inhibits stomach acid production, and commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). It is currently marketed over the counter under the trade name Zantac by Glaxo Smith Klineand by many other companies under various other names.