Zantac is not an antacid, but it is used to prevent and treat heartburn with acid indigestion, according to WebMD. It is an H2 antagonist or histamine H2 blocker medication that is prescribed for the treatment of gastroesophageal reflux disease, or GERD, and other medical conditions that result in the overproduction of stomach acid. Zantac is also sold in its generic version, ranitidine, and may be useful in treating intestinal and stomach ulcers and problems with the throat or esophagus and stomach that result from too much acid being produced by the stomach or acid that flows backward into the esophagus.
The way that Zantac works is by reducing the amount of stomach acid that is produced. This improves symptoms, such as stomach pain and heartburn, and allows ulcers to heal while preventing new ulcers from forming, notes WebMD.
Zantac is available in a prescription formula and an over-the-counter format. Generally, it is taken up to twice daily or as specified by a prescribing physician. It can be taken a maximum of four times daily. The treatment length and dosage recommended varies based on the condition it is used to treat. Usually, one tablet is taken by mouth as needed for heartburn while some doctors recommend taking it before meals to prevent heartburn.