Updated: Aug 11, 2020
Antacids are over-the-counter drugs that help manage symptoms of pain and discomfort caused by heartburn or acid reflux.
They work by neutralizing the stomach acid that irritates the stomach and esophagus.
Examples of antacids you'll find at your local supermarket or pharmacy include:
Tums (calcium carbonate)
Citrical (calcium citrate)
Gaviscon (alginic acid)
Alka-Seltzer (sodium bicarbonate)
Drugs containing a combination of aluminum and magnesium, such as Mylanta, Maalox, and Gelusil
Some of these brands — like Gelusil, Mylanta Extra Strength, and Maalox Advanced — may also contain simethicone to control gas.
Warnings, Precautions, and Drug Interactions
Stop taking antacids and contact your doctor if you've been using antacids for 2 weeks with no improvement in your symptoms.
Ask your doctor before taking antacids if you:
Have kidney or liver problems
Are on a low-sodium diet
Are taking thyroid medication — such as Levoxyl or Synthroid (levothyroxine) — or the blood thinner Coumadin or Jantoven (warfarin), since antacids may interfere with these drugs
If you're pregnant, take care to avoid antacids that contain sodium bicarbonate — like Alka-Seltzer — or are otherwise high in sodium.
If you want a calcium-based antacid but are worried about gas, you may prefer Citrical (calcium citrate) because Tums (calcium carbonate) tends to cause gas.
You can take antacids 30 minutes before you eat, but most people find longer-lasting relief from their symptoms (up to 2 hours) if they take antacids an hour after eating or when their symptoms first appear.
Common Side Effects
Side effects vary based on antacid ingredients, but can include:
Gas or belching
Swelling in the feet, ankles, and hands (products containing sodium bicarbonate, such as Alka-Seltzer)
Constipation (products containing calcium or aluminum)
Diarrhea (products containing magnesium)
Antacids that contain both magnesium and aluminum — like Maalox and Mylanta — are less likely to cause diarrhea or constipation than products containing just magnesium or aluminum, since the effects of these two ingredients tend to balance each other out.