The simplest way to relieve mild heartburn is to swallow repeatedly. Saliva contains the bicarbonate ion (HCO3-) that acts as a base and, when swallowed, neutralizes some of the acid in the esophagus. Later in this chapter, we see how bicarbonate acts as a base. Heartburn can also be treated with antacices such as Tums, milk of magnesia, or Mylanta. These over-the-counter medications contain more base than saliva and therefore do a better job of neutralize the esophageal acid.