Heartburn (pyrosis) is caused by the reflux of acid from the stomach. Common heartburn drugs include: antacids (their purpose is to neutralize the excessive stomach acid causing the pyrosis- they can’t be taken without a prescription), H2 blockers (they also act by decreasing the excessive acidity, blocking the chemicals that produce it), foaming agents (they cover the stomach interior thus preventing reflux of acid from the stomach to the esophagus), proton pump inhibitors PPIs (though they take time until the effect is felt, they offer longer lasting relief, but have a series of side effects), prokinetics (they help the digestive system to work faster by strengthening the esophageal sphincter muscle).