Rantac 300 Tablet is used for the short-term treatment and maintenance after healing of stomach ulcers. This medicine works by reducing the amount of acid in the stomach. This medicine helps by relieving the symptoms of indigestion and heartburn. Rantac 300 is also used to treat a hypersecretory condition in which the stomach produces more amount of acid (Zollinger-Ellison syndrome and systemic mastocytosis), for the short-term treatment and maintenance after healing of stomach ulcers (Active and benign), to treat the symptoms of backflow of stomach acid into the food pipe (gastroesophageal reflexux disease), to treat the inflammation of food pipe and maintenance of healing of inflamed food pipe, to prevent stomach ulcers associated with NSAIDs, treat stomach ulcers due to bacterial infection, post-operative conditions, and digestive disease where stomach acid irritates the food pipe, to prevent digestive tract bleeding due to stress ulceration in ill patients, to prevent repetitive bleeding with bleeding stomach ulcers, to prevent the risk of aspiration of stomach contents during pregnancy before giving anesthesia, and to treat the symptoms of backflow of stomach acid into the food pipe and food pipe inflammation in children. Rantac 300 Tablet may also be used together with other medicines to treat certain conditions as recommended by the doctor. It is used in combination with Antacids to relieve pain in patients with Active or less harmful stomach ulcers, a condition in which stomach produces more amount of acid, and food pipe inflammation.