Antacids are over-the-counter (OTC) medications that help neutralize stomach acid.

They work differently from other acid reducers such as H2 receptor blockers and proton pump inhibitors (PPIs). Those drugs work by reducing or preventing the secretion of stomach acid.

Antacids can be used to treat symptoms of excess stomach acid, such as:

Antacids usually come in the following drug forms:

  • liquid
  • chewable gummy or tablet
  • tablet that you dissolve in water to drink

Popular antacid brands include:

Antacids are typically safe for most people. However, people with certain medical conditions should talk with their doctors before taking certain antacids that contain aluminum hydroxide and magnesium carbonate.

For example, people with heart failure may have sodium restrictions to help decrease fluid buildup. However, antacids often contain a lot of sodium. These people should ask their doctor before using antacids.

People with kidney failure may develop a buildup of aluminum after using antacids. This can lead to aluminum toxicity. People with kidney failure also tend to have problems with electrolyte balance. All antacids contain electrolytes, which could make electrolyte balance problems worse.

Talk to your child’s doctor before giving your child antacids. Children don’t typically develop symptoms of excess stomach acid, so their symptoms could be related to another condition.

Side effects from antacids are rare. However, they can occur, even when you use them according to the directions.

Antacids can either cause constipation or have a laxative effect. Some people have had allergic reactions. Antacids might also increase the risk of developing sensitivities to certain foods.

Side effects from misuse

Many of the side effects of antacids come from not taking them as directed.

Many antacids — including Maalox, Mylanta, Rolaids and Tums — contain calcium. If you take too much or take them for longer than directed, you could get an overdose of calcium. Too much calcium can cause:

Excess calcium can also lead to alkalosis. In this condition, your body doesn’t make enough acid to function properly.

If you feel like you need to use a lot of an antacid for relief, that might be a sign of another condition. If you’ve taken an antacid according to the directions and haven’t gotten relief, talk to your doctor.

Antacids can interfere with the function of other drugs. If you take other medications, check with your doctor or pharmacist before using antacids.

Some antacids, such as Alka-Seltzer, contain aspirin. The Food and Drug Administration issued a safety alert about this type of antacid in June 2016. This alert was issued because of reports of serious bleeding related to aspirin-containing antacids.

If you take another medication that increases your risk of bleeding, such as an anticoagulant or antiplatelet drug, you shouldn’t take these antacids.

Be sure to talk to your doctor before taking aspirin-containing antacids if you:

Antacids can often relieve symptoms of excess stomach acid. However, sometimes these symptoms mean you have a more serious condition.

It’s important that you know how to recognize these conditions and how to respond to them. An upset stomach could actually be gastroesophageal reflux disease (GERD) or a peptic ulcer.

Antacids can only soothe, not cure, some of the symptoms of these conditions. If you have severe pain that doesn’t get better after using the recommended dosage of antacids for two weeks, call your doctor.

Some heart attack symptoms can also mimic stomach pains. You may be having a heart attack if you have severe chest pain that lasts longer than two minutes with any of the following symptoms:

If you think you may be experiencing a heart attack, call 911 or your local emergency services.

If you have acid reflux or other symptoms caused by stomach acidity, get to know your OTC medications.

Antacids neutralize the acid that your stomach makes. This can make you more comfortable. On the other hand, H2 receptor blockers and PPIs can block your stomach from making too much acid. This can allow the damage in your stomach and esophagus to heal.

Ask your doctor which is better for you.