Examples
| Brand Name | Generic Name |
|---|---|
| Maalox, Mylanta | aluminum hydroxide and magnesium hydroxide |
| Gaviscon | aluminum hydroxide and magnesium trisilicate |
| Rolaids, Tums | calcium carbonate |
Antacids are available without a prescription in liquid, chewable tablet, chewing gum, and dissolving tablet forms to be taken by mouth.
How It Works
Antacids make stomach juices less acidic. Less acid in your stomach can make you feel better and reduce your symptoms.
Why It Is Used
- Because acid reducers (H2 blockers and PPIs) do not start to work right away, antacids may be used to give relief of ulcer symptoms during the first few days after a person begins taking an acid reducer. The antacid may be used until the acid reducer is able to control the symptoms.
- Antacids may sometimes be used for a longer period of time (6 to 8 weeks) to help heal an ulcer when the ulcer is not caused by a Helicobacter pylori (H. pylori) infection or by NSAIDs.
How Well It Works
Antacids do not work as well as H2 blockers and PPIs to help ulcers heal. But they can help with ulcer symptoms, and in some cases they may help small ulcers heal.
Antacids may help with the symptoms of some small ulcers but now ulcers caused by Helicobacter pylori (H. pylori) can be cured with antibiotics and there are medicines that work better than antacids for ulcers that are not caused by an infection.
Side Effects
The active ingredients in antacids vary, with the following cautions for each:
- Calcium carbonate (such as Rolaids or Tums) can cause constipation in some people. In rare cases, it can stimulate acid rebound. Acid rebound causes the stomach to produce even more acid, making heartburn worse.
- Magnesium-containing antacids (such as Maalox, Gaviscon, or Mylanta) can cause diarrhea. If used too often by people who have kidney problems, these antacids can lead to too much magnesium in the blood.
- Aluminum-containing antacids (such as Maalox, Gaviscon, or Mylanta) can cause constipation. If used too often by people with chronic kidney failure, these antacids can lead to too much aluminum in the blood.
Some antacid preparations (such as Maalox, Gaviscon, or Mylanta) combine active ingredients to balance side effects. For example, antacids may contain both magnesium and aluminum to prevent diarrhea and constipation.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
While antacids often are able to reduce the symptoms of an ulcer, acid reducers are more effective and provide symptom relief for a longer period of time. An antacid taken at bedtime may not control symptoms throughout the night. You may still be awakened at night with pain from an ulcer.
Antacids and acid reducers should not be taken within 2 hours of each another, because the antacid will slow down the effect of the acid reducers.
Antacids that contain calcium carbonate (such as Rolaids or Tums) may help boost calcium intake, an important benefit for women concerned about developing osteoporosis.
Some antacids may affect how certain antibiotics, digoxin (Lanoxin), and other medicines work. Tell your doctor about all the other medicines you are taking.
Antacids that contain calcium carbonate (such as Tums) are safe to take during pregnancy. If you are pregnant, talk to your doctor before you use antacids.
Antacid therapy is usually less expensive than other treatments.
Liquid antacids may relieve symptoms faster than other forms of antacids.
Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.
| Author: | Monica Rhodes | Last Updated: January 7, 2008 |
| Medical Review: | Kathleen Romito, MD - Family Medicine Andrew H. Soll, MD - Gastroenterology | |


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