Antacids neutralize acids in the stomach, and are the drugs of choice for mild GERD symptoms. They may also stimulate the defensive systems in the stomach by increasing bicarbonate and mucus secretion. They are best used alone for relief of occasional and unpredictable episodes of heartburn. Many antacids are available without a prescription. The different brands all rely on various combinations of three basic ingredients: magnesium, calcium, or aluminum.
Magnesium. Magnesium salts are available in the form of magnesium carbonate, magnesium trisilicate, and most commonly, magnesium hydroxide (Milk of Magnesia). The major side effect of magnesium salts is diarrhea. Magnesium salts offered in combination products with aluminum (Mylanta and Maalox) balance the side effects of diarrhea and constipation.
Calcium. Calcium carbonate (Tums, Titralac, and Alka-2) is a potent and rapid-acting antacid. It can cause constipation. There have been rare cases of elevated levels of calcium in the blood (hypercalcemia) in people taking large doses of calcium carbonate for long periods of time. This condition can lead to kidney failure and is very dangerous. None of the other antacids has this potential side effect.
Aluminum. Aluminum salts (Amphogel, Alternagel) are also available. The most common side effect of antacids containing aluminum salts is constipation. People who take large amounts of antacids that contain aluminum may also be at risk for calcium loss, which can lead to osteoporosis.
Although all antacids work equally well, it is generally believed that liquid antacids work faster and are more potent than tablets. Antacids can interact with a number of drugs in the intestines by reducing their absorption. These drugs include tetracycline, ciprofloxacin (Cipro), propranolol (Inderal), captopril (Capoten), and H2 blockers. Interactions can be avoided by taking the drugs 1 hour before, or 3 hours after taking the antacid. Long-term use of nearly any antacid increases the risk for kidney stones.
Proton Pump Inhibitors
Review Date: 07/11/2010
Reviewed By: Reviewed by: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.