The acid reflux affects the stomach and the esophagus. If the cardiac sphincter fails to close after receiving food from the esophagus, acid reflux occurs. Acid reflux is a chronic condition. Normally, liquid reflux in the stomach occurs to a healthy individual. However, people with the acid reflux or GERD, has more acid in the liquid. Each time individuals swallow the reflux liquid slide back into the stomach. Basically, acid reflux medicines inhibit the production or release of pepsin produced by the chief cells and hydrochloric acid produced by the parietal cells in the stomach. The acid reflux medicines are the Histamine Blockers or the H2 receptor antagonists. Histamine stimulates a pump in the stomach that releases hydrochloric acid.