Nexium vs. Prilosec: Two GERD Treatments

Understanding Your Options

Heartburn is bad enough. Making sense of your medication choices for gastroesophageal reflux disease (GERD) can make it even worse. But there’s a reason for all those options. GERD is a big deal. According to an article in Hepatology, the market for proton pump inhibitors (PPIs), the most commonly prescribed medications for GERD, was $13.9 billion in 2008 in the United States.

Two of the most commonly prescribed PPIs are omeprazole (brand name: Prilosec) and esomeprazole (brand name: Nexium). Both are now available over the counter (OTC). But is there really any difference between them? Take a closer look at both to see what benefits one medication may offer over the other.



Similarities and Differences

Proton pumps are enzymes found in the parietal cells of your stomach. They’re responsible for producing hydrochloric acid, the main ingredient of stomach acid.

Stomach acid isn’t all bad. In fact, your body needs it for digestion. But stomach acid can end up in your esophagus when the muscle between your stomach and esophagus doesn’t close properly. This causes the burning feeling in your chest and throat associated with GERD. It can also cause asthma, coughing, and pneumonia.

Did You Know?
PPIs take effect gradually, so they may not be the answer for occasional heartburn or reflux. Alternatives like chewable calcium carbonate tablets, liquids like aluminum hydroxide and magnesium hydroxide (Maalox) or aluminum/magnesium/simethicone (Mylanta), and acid-reducing drugs like famotidine (Pepcid) or ranitidine (Zantac) (all are available OTC), offer relief for occasional use.

PPIs inhibit the actions of proton pumps. They suppress the amount of acid produced in your stomach. This class of drugs has been in use since 1981. It’s widely considered the most effective medication for reducing stomach acid.

PPIs work best when you take them an hour to half an hour before a meal. You’ll need to take them for several days before they’re fully effective.

Why They’re Prescribed

PPIs like omeprazole and esomeprazole are used to treat gastric acid-related conditions, including:

  • gastro esophageal reflux disease (GERD)
  • heartburn
  • esophagitis (inflammation or erosion of the esophagus)
  • stomach and duodenal ulcers caused by Helicobacter pylori or nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Zollinger-Ellison syndrome (a disease in which tumors cause the production of excessive stomach acid)


Omeprazole was made first, and contained the same drug in two different chemical structures; each one was the mirror image of the other. Esomeprazole is made of just one of those mirror images, with all the molecules of the drug having the same chemical structure. So, the medications are chemically similar.

However, there are minor differences. A number of studies indicate that the differences between the two drugs may offer some advantages to people with certain conditions.

  • A study published in Digestive Diseases and Sciences found that esomeprazole provided more effective control of GERD than omeprazole at the same doses. 
  • According to a study published in World Journal of Gastroenterology, esomeprazole offered faster relief than omeprazole in the first week of use. After one week, symptom relief was similar.

In an article in American Family Physician, doctors questioned these and other studies on PPIs. They cited concerns such as:

  • differences in the amount of active ingredients given in the studies
  • the size of the studies
  • the clinical methods used to measure effectiveness

The authors of the American Family Physician article analyzed 41 studies on the effectiveness of PPIs. They concluded there is very little difference in the effectiveness of PPIs. But there may be big differences in price. Now that both of these drugs are available OTC, you may see dropping prices, as different manufacturers compete.

The Price of Relief

Esophageal Cancer
Over time, GERD can lead to esophageal cancer. Although few people with GERD get esophageal cancer, it’s important to be aware of the risk.

The American Family Physician review of PPIs concluded that the biggest difference between Prilosec and Nexium was price. Until March 2014, Nexium was available only by prescription and at a significantly higher price. Nexium now offers an OTC product that’s priced competitively with Prilosec OTC. However, generic omeprazole may be less expensive than Prilosec OTC.

Traditionally, insurance companies did not cover OTC products. However, the PPI market has led many to revise their coverage of Prilosec OTC and Nexium OTC. If your insurance still doesn’t cover OTC PPIs, a prescription for generic omeprazole or esomeprazole may be your best option.


Side Effects

Side Effects

Most people don’t experience too many side effects from PPIs. Infrequently, people experience:

  • diarrhea
  • nausea
  • vomiting
  • headache

These side effects may be more likely if you take esomeprazole, than if you take omeprazole. 

It’s also believed that both of these PPIs may increase the risk of:

  • spine and wrist fractures in postmenopausal women, especially if the medications are taken for a year or more, or at higher doses
  • bacterial inflammation of the colon, especially after hospitalization
  • pneumonia
  • nutritional deficiencies, including vitamin B-12 and magnesium deficits

There have also been increased rates of stomach cancer in lab animals exposed to omeprazole for two years. It is not known if this risk extends to humans.

Rebound Acid Secretion

Although the process isn’t completely understood, many people experience excess acid production when they stop using PPIs. It’s recommended that you taper off the medication gradually.



Warnings and Interactions

Before taking either medication, tell your doctor if you:

  • are of Asian descent, as your body may take longer to process PPIs and you may need a different dose
  • have liver disease
  • have had low blood levels of magnesium
  • are pregnant or plan on getting pregnant
  • are breastfeeding

Drug Interactions

Prilosec and Plavix Interaction

The U.S. Food and Drug Administration (FDA) has issued a warning that omeprazole (Prilosec) reduces the effectiveness of the blood thinner clopidogrel (Plavix). The FDA recommends that the two drugs not be taken together. Other PPIs are not included in the warning, because they have not been tested for this action.

There are a number of drug interactions with Prilosec.

Always tell your doctor about all the drugs, herbs, and vitamins you’re taking. Both medications can interact with other medications you might be taking.

These drugs should not be taken with either medication:

  • clopidogrel
  • delavirdine
  • nelfinavir
  • pimozide
  • rifampin
  • rilpivirine
  • risedronate
  • St. John’s Wort

Below are some of the drugs that may interact with either medication, but you may still be able to take them. Tell your doctor if you taking any of these drugs:

  • amphetamine
  • aripiprazole
  • atazanavir
  • bisphosphonates (used to prevent bone loss)
  • bosentan
  • carvedilol
  • cilostazol
  • citalopram
  • clozapine
  • cyclosporine
  • dextroamphetamine
  • escitalopram
  • antifungal drugs (fluconazole, ketoconazole, posaconazole or others)
  • fosphenytoin
  • iron
  • hydrocodone
  • mesalamine
  • methotrexate
  • methylphenidate
  • phenytoin
  • raltegravir
  • saquinavir
  • tacrolimus
  • warfarin (or other vitamin K antagonists)
  • voriconazole


How Will You Tame the Fire?

Generally, you can choose the PPI that’s readily available and costs less. But keep in mind that PPIs treat the symptoms of GERD and other disorders — they don’t treat the cause. Lifestyle factors, such as weight management, avoiding big meals right before sleep and quitting tobacco use, should be your first steps in controlling GERD and heartburn.

Article Resources