Antacids are over-the-counter medications that help neutralize stomach acid. They work differently from other acid reducers such as H2-receptor blockers or proton pump inhibitors, which work by reducing or preventing the secretion of stomach acid. Antacids usually come as a liquid, chewable gummy or tablet, or tablet that you dissolve in water to drink. They can be used to treat symptoms of excess stomach acid, such as:

  • acid reflux, which can include regurgitation, bitter taste, persistent dry cough, pain when you lie down, and trouble swallowing
  • heartburn, which is a burning sensation in your chest or throat caused by acid reflux
  • indigestion, which is pain in your upper gut that can feel like gas or bloating

Popular antacids include:

  • Alka-Seltzer
  • Maalox
  • Mylanta
  • Rolaids
  • Tums

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. These antacids often contain a lot of sodium, though. These people should ask their doctor before using antacids.

People with kidney failure may develop a buildup of aluminum from these products. 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 happen, even when you use them according to directions. Antacids can cause constipation. In some cases, they can have a laxative effect instead. 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, such as such as 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:

  • nausea
  • vomiting
  • mental status changes
  • kidney stones

Excess calcium can also lead to a condition called 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, like Alka-Seltzer, contain aspirin. The U.S. 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 antiplatelet or anticoagulant drug, you shouldn’t take these antacids.

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

  • have a history of stomach ulcers or bleeding disorders
  • are older than 60 years
  • drink three or more alcoholic drinks per day

Antacids can often relieve symptoms of excess stomach acid. However, sometimes these symptoms mean you have more serious condition. It is important that you know how to recognize these conditions and what to do.

An upset stomach could actually be gastroesophageal reflux disease 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:

  • lightheadedness
  • shortness of breath
  • pain that radiates to your arms or shoulders and jaw
  • neck or back pain
  • vomiting or nausea

If you think you may be experiencing a heart attack, call 911.

If you have acid reflux or other symptoms from stomach acidity, know your medications. Antacids neutralize the acid that your stomach makes. This can make you more comfortable. On the other hand, H2-receptor blockers and proton-pump inhibitors can block your stomach from making too much acid. This can allow the damage in your stomach and esophagus to heal. Ask your doctor about which is better for you.