1. Antacids work to neutralise stomach acid. They are used to relieve acid indigestion, upset stomach, sour stomach, and heartburn.
2. Antacids are taken by mouth. They contain ingredients such as aluminum hydroxide, calcium carbonate, magnesium hydroxide, and sodium bicarbonate, alone or in various combinations. Antacid products may also contain other ingredients such as simethicone, which relieves gas.
3. Antacids containing aluminum hydroxide or calcium carbonate can weaken protein digestion, and lead to constipation. While antacids containing magnesium hydroxide, or sodium bicarbonate, may cause diarrhoea. For this reason, the combination therapy is much better.
4. Antacids differ in how quickly they work and how long they provide relief. Those that dissolve rapidly in the stomach, such as magnesium hydroxide and sodium bicarbonate, bring the fastest relief. Antacids that contain calcium carbonate or aluminum dissolve more slowly and can take up to 30 minutes to begin working. The longer an antacid stays in the stomach, the longer it works.
5. Antacids are meant to be used only occasionally. They should not be taken continuously for more than two weeks unless under a physician's directions. Taking antacids over long periods could mask the symptoms of a serious stomach or intestinal problem, such as peptic ulcer disease. Older people should be especially careful, as they may have ulcers without showing the typical symptoms.
6. If any signs of appendicitis or inflamed bowel are present, antacids should not be taken. Symptoms of appendicitis include cramping, pain, and soreness in the lower abdomen, bloating, and nausea and vomiting. Anyone whose symptoms do not improve after taking antacids or who has black, tarry stools should call a physician. These symptoms could be signs of a serious condition that needs medical attention.
7. Antacids, especially ones that contain aluminum, can interfere with Calcium, Zinc, and Magnesium absorption and function. It is not uncommon for the elderly to over consume antacids due to frequent and reoccurring indigestion, and heartburn, and thus encourage mineral deficiencies. Antacids may interact with many other medicines. When this happens, the effects of one or both drugs may change, or the risk of side effects may be greater. Anyone taking a prescription drug should check with his or her physician before taking antacids.
8. Side effects are very rare when antacids are taken as directed. They are more likely when the medicine is taken in large doses or over a long time. Minor side effects include a chalky taste, mild constipation or diarrhea, thirst, stomach cramps, and whitish or speckled stools. These symptoms do not need medical attention unless they do not go away or they interfere with normal activities.
9. Other uncommon side effects may occur. Anyone who has unusual symptoms after taking antacids should get in touch with his or her physician.
10. If there are children around, you have to find an area where you can lock up your antacids. This medication should be stored in a dry place away from heat and humidity. Antacid suspension need not to be refrigerated.

The write up is compiled by Muhammad Arifur Rahman, Asst. professor of Dpt of Pharmacy, Daffodil International University.