Antacids and Their Effects on Heartburn and Indigestion

Medically reviewed by Mary Choy, PharmDMedically reviewed by Mary Choy, PharmD

Antacids are medications that can be purchased over-the-counter (OTC) and are used to treat conditions associated with excess stomach acid, such as heartburn, acid reflux, and sour stomach.

Antacids contain earth metals, including calcium, sodium, magnesium, and aluminum, that react with hydrogen ions to help neutralize stomach acid. Taking too much of these medications can lead to a high level of these elements in the body, which may cause heart rhythm disturbances, diarrhea, or constipation, among other possible issues.

Understanding Antacids

What Are Antacids and How Do They Work?

Stomach acid is essential for digesting food and killing bacteria, but too much of it can lead to heartburn and other uncomfortable symptoms.

pH is a measure that indicates the concentration of hydrogen ions in a solution, like your stomach acid. The lower this number is, the more hydrogen ions there are and the more acidic the environment is. A pH level of 7 is neutral, below 7 is acidic and above 7 and up to 14 is basic or alkaline.

Antacids contain ingredients like aluminum, calcium, magnesium, or sodium. These are all called alkaline earth metals and are elements that react with acidic stomach acid to neutralize it, slightly increase pH, and relieve symptoms like sour taste in the mouth, bloating, and pain in the chest or stomach area.

Types of Antacids

This table displays antacids that are available OTC along with their most common brand names seen on store shelves.

You may see other medications on store shelves that also advertise their ability to neutralize stomach acid or treat heartburn. These medications work differently from antacids but ultimately have similar effects. Some are available OTC, and some require a prescription.

• Proton-pump inhibitors (PPIs) reduce stomach acid production by binding to proton pumps, which are located on the walls of your stomach and release hydrogen ions that make environments more acidic. Examples are Prilosec (omeprazole) and Nexium (esomeprazole).

• Histamine-2 receptor antagonists, also known as H2-blockers, block histamine receptors that signal stomach cells to release more acid. Examples include Pepcid (famotidine) and Zantac (ranitidine).

Precautions

Kidney Failure

Some antacids have the potential to cause kidney damage if they’re used regularly over a long period. The kidneys filter antacids from your body after you take them. Kidneys that are impaired may not be effectively able to filter these drugs, which can lead to build-up and damage.

Antacids that contain aluminum and magnesium, such as Maalox and Mylanta, may lead to high levels of these ingredients in the body, which can cause:

• Kidney stones

• Cardiovascular problems

• Muscle weakness

• Confusion

If you have kidney issues, you should generally avoid or take these antacids only occasionally. It is best to discuss the safest options for managing heartburn and stomach acid with your healthcare provider.

Heart Disease

While correlations are still being studied, studies have shown that people who take PPIs (like Prilosec or Nexium) long-term are at a higher risk for cardiovascular events like heart attack compared to those who do not take PPIs. This is thought to be due to the harmful effects of PPIs on proper endothelial function–which is needed for efficient blood circulation.

Apart from PPIs, long-term frequent use of antacids like calcium carbonate may lead to low magnesium levels, which can lead to heart rhythm issues, and/or high calcium levels, which can speed up plaque formation in the arteries. For this reason, antacids should only be used occasionally. If you need to use them regularly, bring this up with your healthcare provider.

A safer antacid option for heart health may be H2-blockers, like Pepcid or Zantac. However, not enough research exists to confirm their improved safety profile.

Interactions

Can You Safely Take Antacids With Other Medications?

There are many important interactions to be aware of between antacids and other medications. It's also important not to take other medications within 2 to 4 hours of taking an antacid.

Decreased absorption:

• Some drugs rely on an acidic environment to be properly absorbed, so decreasing stomach acid may lower levels of these drugs in the body and decrease their effects. Examples include digoxin, chlorpromazine, and isoniazid.

• Magnesium-containing antacids can bind to some antibiotics such as tetracycline, doxycycline, Levaquin (levofloxacin), and Cipro (ciprofloxacin), lowering their levels and making them less effective.

Increased absorption:

Nonsteroidal anti-inflammatory drugs (NSAIDs) like Motrin (ibuprofen) and sulfonylurea diabetes medications like Glucotrol (glipizide) and Amaryl (glimepiride) may be absorbed more than normal when taken with antacids, increasing their levels, and potential side effects.

Can You Mix Antacids With Alcohol?

It is generally safe to take antacids with alcohol if both are used in moderation. Long-term alcohol use or abuse has a well-studied link to gastritis, indigestion, heartburn, and other issues that will require increased long-term use of antacids, causing further issues.

Side Effects

Most antacids have overlapping potential side effects, including abdominal pain or cramping, nausea or vomiting, and constipation or diarrhea. Some additional, more serious side effects to be aware of for specific products include:

For aluminum hydroxide-based antacids:

• Osteopenia: low bone density

• Osteomalacia: softer, less mineralized bones

• Microcytic anemia: decreased red blood cell size due to lack of hemoglobin

• Fecal impaction: a severe form of constipation

• Hypomagnesemia: low magnesium levels

• Hypophosphatemia: low phosphate levels

Calcium carbonate based antacids:

• Flatulence: passing gas

• Xerostomia: dry mouth

• Headache

• Hypercalcemia: high calcium levels

• Hypophosphatemia: low phosphate levels

Summary

Occasional heartburn or indigestion is normal and experienced by most people. Your stomach needs to be an acidic environment to digest food and keep bacteria at bay. Too much stomach acid can produce uncomfortable symptoms, which antacids can help calm.

However, overusing antacids may have dangerous effects, and you should make your healthcare provider and pharmacist aware of your full medication list (including over-the-counter medications and supplements) to avoid antacid interactions with some common medications.

If you need to use antacids more often than two or three times per week, you should speak with your healthcare provider to help address the root cause and come up with the safest treatment plan.

Read the original article on Verywell Health.