Axid is a brand name for Nizatidine, a histamine-2 blocker. It reduces the amount of acid produced in the stomach and is often used to treat conditions such as gastroesophageal reflux disease (GERD) and gastric ulcers. There are several synonyms for this medication, including Nizatidine, Tazac, and Zantac. These medications work in a similar way, and you should always consult with your healthcare provider and follow their advice on which medication is best for your individual needs. It's important to take the medication as directed and not to stop taking it without consulting your healthcare provider first.