Nexium is a prescription drug used to treat gastroesophageal reflux disease (GERD), acid reflux, and other conditions. It may also be used how to get cheap nexium without a prescription lower the risk of cancer in people with chronic stomach inflammation. Nexium is an antacid that lowers the amount of acid released by your stomach and helps protect the esophagus from stomach acid. It is meant for long-term use only.