Ranitidine is a medicine that reduces the amount of acid your stomach makes; it's classified as an H2 receptor antagonist (also known as an H2 blocker). It was commonly used to treat conditions like indigestion, heartburn, acid reflux, gastro-oesophageal reflux disease (GORD), and stomach ulcers.
In more detail, ranitidine worked by blocking histamine from stimulating acid-producing cells in the stomach. By reducing stomach acid production, it helped to relieve symptoms and promote healing of the affected tissues.
Important Note: Ranitidine has been recalled from the market in many countries due to the presence of an impurity called N-nitrosodimethylamine (NDMA), which is a probable human carcinogen. It's crucial to consult with a doctor or pharmacist about safer alternative medications if you were previously taking ranitidine.