Esomeprazole: everything you need to know

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Chimene Richa, MD 

Mike Bohl, MD, MPH, ALM - Contributor Avatar

Written by Chimene Richa, MD 

last updated: Oct 02, 2020

6 min read

What is esomeprazole and how does it work?

Esomeprazole (brand name Nexium) is a medication that helps decrease the production of stomach acid. It is used to treat conditions like heartburn, gastrointestinal reflux (GERD), and stomach ulcers. 

Esomeprazole comes in various forms linked to different salts: esomeprazole magnesium (delayed-release and liquid), esomeprazole strontium (delayed-release), and esomeprazole sodium (intravenous). These forms differ in terms of how you take them, but all work the same way. 

Esomeprazole is part of the proton pump inhibitor (PPI) class of drugs, which also includes omeprazole, lansoprazole, and pantoprazole. Proton pump inhibitors act on specialized pumps in stomach cells, called proton pumps, responsible for producing stomach acid (DailyMed, 2020). 

These proton pumps are responsible for secreting stomach acid; by inhibiting them, esomeprazole decreases the amount of acid that the stomach makes. However, if you are thinking of starting esomeprazole, know that it does not start working right away—it can take 1–4 days for the drug to take effect (MedlinePlus, 2020).


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What is esomeprazole used for

Esomeprazole is FDA-approved for the following conditions (FDA, 2014): 

  • Gastroesophageal reflux disease (GERD)

  • Prevent gastric (stomach) ulcers from NSAIDs

  • Treat Helicobacter pylori (H. pylori) infections and prevent duodenal (intestinal) ulcers

  • Zollinger-Ellison syndrome

Gastroesophageal reflux disease (GERD):

GERD (also called “acid reflux”) is a medical condition that causes discomfort when stomach acid flows backward up the esophagus. Occasional episodes of reflux are expected; however, if you find that you are experiencing frequent symptoms, you may have GERD. Heartburn, regurgitation (food rising in the back of your throat), a sour taste in your mouth, sore throat, and chronic cough are some of the common symptoms of GERD (Kahrilas, 2020).

Unfortunately, GERD causes more problems than just some uncomfortable symptoms. Excess acid reflux can damage your esophagus (the tube that connects your mouth to your stomach). Barrett’s esophagus is a condition in which the lining of the esophagus becomes thickened from all of the stomach acids. While this sounds bad enough, Barrett’s esophagus may also increase your risk of getting esophageal cancer. GERD can also cause erosive esophagitis—sores and erosions in your esophagus (Kahrilas, 2020).

By decreasing the production of stomach acid, PPIs like esomeprazole help improve your symptoms and reduce the damage to your esophagus.

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Stomach ulcers from NSAIDs

Stomach ulcers (gastric ulcers) frequently result from taking too many non-steroidal anti-inflammatory drugs (NSAIDs), like aspirin, ibuprofen, or naproxen. Taking NSAIDs makes you four times as likely to develop stomach ulcers or duodenal (intestinal ulcers), also known as peptic ulcer disease (Vakil, 2020). Also, people who take NSAIDs and develop stomach ulcers have a higher risk of complications from those ulcers.

Esomeprazole can help by decreasing the chance of developing gastric ulcers in people who have to be on long-term NSAID therapy and are at high risk of getting ulcers. This high-risk group includes people over 60 years of age and/or those who have had stomach ulcers in the past. 

H.pylori infections causing duodenal (intestinal) ulcers

H. pylori is a bacteria that infects your stomach and causes ulcers in your stomach and duodenum. Approximately 30–40% of Americans get infected with H. pylori, most often during childhood (MedlinePlus, n.d.). If you have H. pylori, you are 6–10 times more likely to develop duodenal ulcers or stomach ulcers than people without the bacteria (Vakil, 2020).

Duodenal ulcers from H. pylori are often treated with a combination of antibiotics and PPIs, like esomeprazole. This “triple therapy” usually involves esomeprazole, and the antibiotics amoxicillin and clarithromycin (DailyMed, 2020).

Zollinger-Ellison Syndrome (ZES)

ZES, a type of hypersecretory condition, occurs when abnormal growths (called gastrinomas) form in the pancreas or the upper part of the small intestine. These growths release a substance called gastrin, which is a hormone that tells the stomach to secrete more acid. People with ZES produce so much acid that they often develop heartburn, along with gastric and duodenal ulcers. Esomeprazole helps by decreasing stomach acid production and improving symptoms.

Side effects of esomeprazole

Common side effects of omeprazole include (DailyMed, 2020):

  • Headaches

  • Diarrhea

  • Nausea

  • Flatulence (gas)

  • Abdominal pain

  • Constipation

  • Dry mouth

 Serious side effects (DailyMed, 2020):

  • Acute interstitial nephritis: Some people who take esomeprazole develop an allergic (hypersensitivity) reaction that affects their kidneys—this can happen at any point during treatment and is called interstitial nephritis. Fortunately, for most people, interstitial nephritis improves after stopping esomeprazole. 

  • Clostridium difficile taking esomeprazole increases your risk of developing Clostridium difficile- (C. diff-) associated diarrhea, especially if you are in the hospital. 

  • Bone fractures: Long-term esomeprazole use makes you more likely to experience osteoporosis-related bone fractures of the hip, wrist, or spine. If you are going to be taking esomeprazole for a year or longer, consider taking calcium and vitamin D supplements (UpToDate, n.d.).

  • Cutaneous lupus erythematosus (CLE) and systemic lupus erythematosus (SLE): Certain autoimmune diseases, like cutaneous lupus erythematosus (CLE) or, less commonly, systemic lupus erythematosus (SLE) can develop or get worse in people taking esomeprazole. Most people improve after stopping esomeprazole. 

  • Vitamin B12 (cyanocobalamin) deficiency: Using esomeprazole for more than two years may decrease the absorption of vitamin B12 and lead to a deficiency. Women under 30 are at increased risk, and the vitamin B12 deficiency seems to be worse with higher doses of esomeprazole; this improves after stopping the medication (UpToDate, n.d.). 

  • Low levels of magnesium (hypomagnesemia): Taking esomeprazole for more than three months (in most cases for more than one year) can cause a drop in magnesium levels, especially if taken with other drugs that also lower magnesium (like diuretics). Hypomagnesemia does not always cause symptoms, but it can lead to muscle spasms (tetany), abnormal heart rhythms (arrhythmias), and seizures.

  • Fundic gastric polyps: Fundic gastric polyps can occur in people who use esomeprazole for long-term therapy, especially for more than one year. These polyps are small masses in the upper part of the stomach (fundus) and are not cancerous. Most of the time, they do not cause any symptoms and are seen incidentally on endoscopy.

This list does not include all possible side effects of esomeprazole, and others may occur. Seek medical advice from your pharmacist or healthcare provider for more information. 

Drug interactions

Before starting any medicines, be sure to seek medical advice to discuss any potential drug interactions. Drug interactions include (DailyMed, 2020):

  • Clopidogrel (brand name Plavix): Esomeprazole interferes with the ability of clopidogrel (a blood thinner) to stop platelets from clumping. If you are taking esomeprazole, consider using a different blood thinner. 

  • St. John’s Wort These medications interact with the cytochrome P450 system in the liver and decrease the effectiveness of esomeprazole. 

  • Methotrexate: Taking methotrexate with esomeprazole may increase your methotrexate levels, potentially causing methotrexate toxicity. 

  • HIV antiviral drugs: Using atazanavir (brand name Reyataz) and nelfinavir (brand name Viracept) in combination with esomeprazole decreases the levels of both antiviral medicines. This makes them less effective at fighting off an HIV infection and increases the risk of developing drug-resistance. However, taking saquinavir with esomeprazole raises antiviral levels, potentially leading to saquinavir toxicity. 

  • Tacrolimus: Esomeprazole may increase your blood levels of tacrolimus (a drug for transplant recipients to prevent graft rejection).

  • Drugs whose metabolism requires stomach acids: Drugs like ketoconazole, iron salts, erlotinib, and mycophenolate mofetil need the low pH from stomach acid to work. Taking esomeprazole can decrease the effectiveness of these medicines.

  • Digoxin: Esomeprazole raises your blood levels of digoxin, increasing the risk of toxicity.

  • Warfarin (brand name Coumadin): Taking warfarin with esomeprazole may lead to an increased risk of bleeding.

This list does not include all possible drug interactions with esomeprazole and others may exist. Check with your pharmacist or healthcare provider for more information.

Who should not use esomeprazole (or use it with caution) 

Certain groups of people should avoid using esomeprazole or use it with caution (UpToDate, n.d.):

  • Pregnant women: Esomeprazole is classified as pregnancy category C, which means that there is not enough information to determine the risk to the pregnancy (FDA, 2014). Women and their healthcare providers should weigh the benefits of esomeprazole against the risk to the fetus.

  • Nursing mothers: Esomeprazole does get into the breastmilk, but no adverse effects have been reported. Use caution if breastfeeding while taking esomeprazole. 

  • People with liver disease: Since the liver breaks down esomeprazole, people with liver disease may have difficulty metabolizing the drug and end up with higher than expected levels in their system—they may need a lower dose of esomeprazole.

  • People with lupus: If you have cutaneous lupus erythematosus or systemic lupus erythematosus, taking esomeprazole increases your risk of worsening lupus symptoms.

  • People with osteoporosis: Esomeprazole increases your risk of bone fractures. If you already have osteoporosis, use esomeprazole with caution. 

This list does not include all possible at-risk groups and others may exist. Talk to your pharmacist or healthcare provider for more information.


Esomeprazole (brand name Nexium) comes in three different forms: esomeprazole magnesium, esomeprazole strontium, and esomeprazole sodium. Esomeprazole magnesium comes as both delayed-release pills (20 mg and 40 mg strengths) and a liquid (2.5 mg, 5 mg, 10 mg, 20 mg, 40 mg strengths). Esomeprazole strontium comes in delayed-release 49.3 mg capsules. The intravenous (IV) injectable formulation is only available with esomeprazole sodium and comes in 40 mg strength. 

Esomeprazole magnesium 20 mg pills are also available over the counter, either as a generic or under the brand name Nexium 24HR. Most insurance plans cover prescription esomeprazole, and the cost for a 30-day supply ranges from $12 to over $200, depending on the form and strength. 


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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Current version

October 02, 2020

Written by

Chimene Richa, MD

Fact checked by

Mike Bohl, MD, MPH, ALM

About the medical reviewer

Dr. Mike is a licensed physician and a former Director, Medical Content & Education at Ro.