This brand of antacid drugs contains the active ingredients calcium carbonate and magnesium hydroxide. These are the active ingredients that are used to treat indigestion and heartburn. The antacid drugs also have a number of other active ingredients that work in synergy with the active ingredients to produce a desired effect. Antacid drugs can be found in a variety of strengths and forms, with each of these having different effects on the body. Some antacid drugs may be over-the-counter (OTC) and others may be prescription only. Antacid drugs are typically used to combat stomach acid, but some may also be used to reduce heartburn and prevent ulcers.