Antacids are taken to relieve heartburn or indigestion caused by excess stomach acid. While they are safe if used occasionally, antacids may cause problems if taken regularly. There are several kinds of antacids. Learn what ingredients are in each type so that you can avoid any adverse effects.

• Sodium bicarbonate antacids (such as Alka-Seltzer and Bromo Seltzer) contain baking soda. Avoid these antacids if you have high blood pressure or are on a salt-restricted diet. Alka-Seltzer contains aspirin, which is linked to Reye’s syndrome, a rare but serious illness in children.
• Calcium carbonate antacids (such as Tums and Alka-Mints) are sometimes used as calcium supplements. These products may cause constipation.
• Aluminum-based antacids (such as Amphojel) are less potent and work more slowly than other products do. They may also cause constipation. Some may cause calcium loss and should not be taken by postmenopausal women. If you have kidney problems, check with your doctor before using aluminum-based antacids.
• Magnesium compounds (such as Phillips' Milk of Magnesia) may cause diarrhea.
• Aluminum-magnesium antacids (such as Maalox, Di-Gel, Mylanta, and Riopan) are less likely to cause constipation or diarrhea than are aluminum-only or magnesium-only antacids.

Acid reducers decrease the amount of acid produced by the stomach. There are several types of nonprescription acid reducers on the market. Each has slightly different cautions for use. Read and carefully follow the instructions included with the package.

Antacid and acid reducer precautions

• Try to eliminate the cause of frequent heartburn instead of taking antacids regularly. For more information, see the topic Heartburn.
• Consult your doctor or pharmacist before taking an antacid if you take other medicines. Antacids may interfere with the absorption and action of some prescription medicines. Also consult your doctor if you have ulcers or kidney problems.
• If you have a problem with the function of your kidneys or liver, you should be careful in using acid reducers. All drugs are broken down and removed from the body by the combined action of the liver and kidneys. If your liver or kidneys are not working correctly, it is possible that too much of the acid-reducing drug will build up in your body.