Antacid is any of a group of drugs that neutralize acid in the digestive system. Hydrochloric acid, produced in the stomach, is important to digestion. However, this acid can cause pain when it comes in contact with peptic ulcers, sores that can occur in the lining of the esophagus, stomach, or duodenum (first part of the small intestine). Antacids help relieve or prevent pain associated with peptic ulcers by neutralizing this acid. People also take antacids to stop the pain of heartburn and indigestion.
Many antacid products contain compounds of aluminum, magnesium, or, often, both. These chemicals react with acids to form more neutral compounds that do not irritate peptic ulcers. By relieving irritation, antacids also can help promote healing of the ulcers. Many doctors recommend their use along with other antiulcer drugs, such as antibiotics and histamine H2-receptor antagonists (for example, cimetidine).
Antacids come in tablet, capsule, and liquid form. Commonly used antacids include such brand-name products as Maalox and Mylanta. Tums, another common antacid, contains a compound of calcium that is helpful for digestion but not recommended for ulcer treatment. These drugs ordinarily do not cause harmful side effects, and a doctor’s prescription is not needed to purchase them. However, antacids that contain magnesium hydroxide can cause diarrhea, while those with aluminum hydroxide can cause constipation. Problems also may develop when antacids are used for long periods. For example, extensive use of antacids that contain calcium carbonate can cause too much calcium to accumulate in the body. High calcium levels can lead to kidney damage and other problems.
