Nexium Vs Prilosec


Nexium and Prilosec are both proton pump inhibitors (PPIs) used commonly for treating the symptoms of Gastroesophageal Reflux Disease (GERD) and heartburn. While both medications are used to treat similar conditions but have slight differences in their chemical markup.

Both are used to reduce stomach acid and prevent acid reflux symptoms. While Nexium has been found to perform better in terms of short-term outcomes, both have similar effectiveness levels in terms of long-term effects.

About Nexium and Prilosec

What is Nexium?

Nexium is the brand name of Esomeprazole, and it received its first FD approval in 2001. This drug helps in treating the symptoms of heartburn, GERD, and other conditions, like Zollinger-Ellison syndrome. It promotes erosive esophagitis healing, which occurs when stomach acid damages the esophagus. It is among the widely used pills in the country for stomach acid-related problems. This medication has four different versions, including:

  • Prescription Nexium manufactured by AstraZeneca for the treatment of severe acid-related disorders.
  • Generic Nexium is available as an over-the-counter and prescription formulation.
  • OTC Nexium 24HR, an over-the-counter version manufactured by Pfizer and approved by the FDA for the treatment of chronic heartburn
  • Store Brand Nexium 24HR is widely available under multiple retailers brands, like Walgreens and Walmart.

In all these versions, Esomeprazole is the most active ingredient.

What conditions is Nexium approved to treat?

Nexium is used to treat severe stomach acid problems in children (over one year) and adults. It may also be used as a way to prevent stomach ulcers in patients using NSAIDs and to prevent bacteria-causing stomach ulcers.

Nexium has been approved by FDA for the treatment of the following conditions:

  • Erosive esophagitis
  • Frequent heartburn (only OTC versions)
  • Gastroesophageal reflux disease (GERD)
  • Stomach ulcers
  • Zollinger-Ellison syndrome

The OTC Nexium is ideal to be used for those who suffer from heartburn over two days every week. It is important to note that Nexium is not for sudden heartburn treatment but can be used to manage acid problems.

How does Nexium work for Heartburn?

Being a proton pump inhibitor, Nexium reduces the amount of acid present in the stomach and its product by irreversibly blocking the enzymes that are creating the acid, known as gastric proton pump or H+/K+ ATPase.

This proton pump is situated in the stomach wall's parietal cells. The medicine affects both stimulated and baseline gastric acid secretion. It also heals the damaged tissues in the duodenum, stomach, and esophagus.

What is Prilosec?

Prilosec is the brand name of Omeprazole, and it received its first FDA approval in 1990. This drug is also a proton pump inhibitor used as a treatment for serious stomach acid conditions and esophagus issues like acid reflux. Prilosec OTC also helps in treating frequent heartburn. It helps in managing symptoms like cough and swallowing difficulties. The pill also heals the esophagus and stomach damage caused by stomach acid while also preventing ulcers.

What conditions is Prilosec approved to treat?

Prilosec was approved as a prescription medication in 1989 by FDA, and it has since been used to treat various stomach problems caused due to stomach acid. It has not been approved for the treatment of simple heartburn but is approved for frequent heartburn (occurring for over two days in a week).

This medication has been approved by FDA for the treatment of the following conditions:

  • Active duodenal ulcer
  • Erosive esophagitis (EE)
  • Gastroesophageal reflux disease (GERD)
  • Helicobacter pylori
  • Hypersecretory conditions
  • Stomach ulcers

How does Prilosec work for Heartburn?

Prilosec helps treat heartburn by lowering the amount of acid produced by the stomach. It does so by shutting down the small pumps situated in the stomach that is responsible for creating the acid. This reduces the amount of acid and enhances the healing process.


How effective are Nexium and Prilosec for treating GERD and Heartburn?

Nexium and Prilosec are similar medications but with slightly different chemical makeup. Prilosec includes two omeprazole isomers, while Nexium contains one. Isomers are molecules with the same chemicals but different arrangements. This indicates that Nexium and Prilosec have a similar foundation but are built differently.

Although this might seem like a minor difference, it creates a major difference in how these two medications work. For instance, the isomer in Nexium processes slowly in the body compared to the isomer in Prilosec. This shows that there are higher drug levels in the blood, and Nexium can potentially reduce the production of acid for a longer duration.

Nexium might also work faster in treating the symptoms than Prilosec. Moreover, Nexium is metabolized differently in the liver, leading to fewer drug interactions compared to Prilosec. Studies have shown that the differences between these two drugs may provide certain advantages for patients suffering from certain conditions.

A study showed that Nexium has better control of the symptoms of GERD than Prilosec when taken in exact dosages. Another study found that Nexium was more efficient in treating heartburn symptoms than a placebo, and a review of eight studies showed that 20 mg of Nexium can treat GERD symptoms faster.

Some clinical trials found that Nexium has the tendency to outperform other PPIs, including Prilosec, when it comes to treating the symptoms of gastro-oesophageal reflux. Nexium was also found to provide more efficient acid control and quicker symptom relief for patients with reflux esophagitis.

How is Prilosec administered for Heartburn?

Prilosec dosage information

The dose of Prilosec is based on the condition to be treated. While 20 to 40 mg of Prilosec per day can treat most conditions, conditions like GERD might require a higher dose based on the doctor's recommendation.

Side Effects

What are the most common side effects of Nexium?

Some of the common side effects of this medication include:

  • Headache
  • Abdominal pain
  • Diarrhea
  • Nausea
  • Dry mouth or an unusual taste
  • Decreased appetite
  • Constipation
  • Flatulence

Infants taking Nexium might experience regurgitation and rapid breathing. Children might also experience drowsiness.

Are there any potentially serious side effects of Nexium?

In most cases, individuals can easily tolerate Nexium, but some might experience severe side effects, including:

  • Allergic reactions
  • Appetite loss or severe nausea
  • Blisters, hives, peeling skin, polyps, or rashes
  • Bloody stool or severe diarrhea or
  • Changes in urination frequency or bloody urine
  • Excessive tiredness, lightheadedness, or dizziness
  • Fever
  • Hoarseness or difficulty swallowing
  • Irregular heartbeat or breathing difficulties
  • Jaundice or yellowing of the eyes and skin
  • Swelling, muscle weakness or cramps, joint pain
  • Uncontrollable shaking, seizures, or jitteriness
  • Vitamin B-12 deficiency, irregular blood cell count, or elevated liver enzymes

It may also increase the risk of developing systemic lupus erythematosus (SLE) and cutaneous lupus erythematosus (CLE). The medication might also cause bone fractures and kidney damage.

In rare cases, patients taking Nexium have also reported autoimmune issues, hepatitis, and blurred vision. Since these side effects were reported outside the clinical trials, there isn't any verification of whether these are linked to the medication.

* If you experience any of these serious side effects, seek medical help immediately

Are there the most common side effects of Prilosec?

Some common side effects of this medication include:

  • Constipation
  • Cough
  • Diarrhea
  • Dizziness
  • Fever (in children)
  • Gas
  • Headache
  • Nausea
  • Rash
  • Respiratory system symptoms (in children)
  • Sore throat
  • Stomach pain
  • Vomiting

Are there any potential serious side effects of Prilosec?

FDA included warnings regarding Prilosec's severe side effects and dangers in 2022. Although these are rare but may include:

  • Acute Interstitial Nephritis (AIN)
  • Bone fracture of the spine, wrist, or hip
  • Clostridium difficile-associated diarrhea
  • Deficiency of vitamin B-12
  • Kidney failure, damage, or injury
  • Low magnesium levels
  • Lupus Erythematosus

* If you experience any of these severe side effects, seek medical help immediately

There is also a higher possibility of overdose with Prilosec. Some early symptoms of the overdose include:

  • Blurred vision
  • Confusion
  • Dry mouth
  • Flushing
  • Headache
  • Increased sweating
  • Passing out
  • Trouble breathing

* If you experience any of these symptoms or see anyone experiencing these symptoms, seek medical help immediately

Contraindications and Interactions

Warnings and general precautions for Nexium and Prilosec

Nexium and Prilosec are not recommended for breastfeeding and pregnant women. A study also found that Prilosec may enhance the stroke and heart attack risk. Another study found a higher risk of bone fractures among children using Prilosec, particularly those children who received PPIs before turning one.

It is integral to assess the warnings and precautions for Nexium and Prilosec before taking them. It is ideal to consult a medical health professional to ensure these medications are right for you.

Contraindications and important interactions for Nexium and Prilosec



Nexium has been found to be contraindicated among those with hypersensitivity to formulation components or substituted benzimidazoles.

The symptoms of hypersensitivity might include urticarial, anaphylaxis, acute tubulointerstitial nephritis, angioedema, anaphylactic shock, and bronchospasm.

Nexium may produce allergic reactions in those using medications or products containing rilpivirine and Esomeprazole.


Prilosec has been found to be contraindicated among patients with hypersensitivity to any formulation component or substituted benzimidazoles. The symptoms of hypersensitivity might include urticarial, acute tubulointerstitial nephritis, bronchospasm, angioedema, anaphylactic shock, and anaphylaxis.

Prilosec and other PPIs have been found to be contraindicated among patients taking rilpivirine-containing medication or products.

Drug/Medication Interactions


  • Any CYP2C19 drugs
  • Atazanavir
  • Calcium carbonate
  • Cilostazol
  • Clopidogrel
  • Clozapine
  • Dapsone
  • Diazepam
  • Digoxin
  • Indinavir
  • Iron
  • Itraconazole
  • Ketoconazole
  • Methotrexate
  • Mycophenolate
  • Nelfinavir
  • Penicillins
  • Saquinavir
  • Tacrolimus
  • Vitamin B12
  • Warfarin


  • Ampicillin
  • Calcium carbonate
  • Citalopram
  • CycloSPORINE
  • Diazepam
  • Digoxin
  • Disulfiram
  • Flurazepam
  • Gefitinib
  • Indinavir
  • Iron salts
  • Ketoconazole
  • Methotrexate
  • Phenytoin
  • Plavix
  • St. John’s wort
  • Triazolam
  • Vitamin B12
  • Warfarin

Food/Beverage/Supplement Interactions


Food could impact the absorption of the medication. It is best to take Nexium an hour before or after meals. The same goes for patients being given nutrition through tube feedings.

Drinking alcohol with Nexium doesn't create any issues, but alcohol might worsen the symptoms of acid reflux for some individuals.


There aren’t any interactions found between Prilosec and any food and supplement.

While alcohol or other beverages don't affect the working of this medication, it is best to avoid drinking alcohol as the symptoms might worsen since alcohol creates more acid in the stomach.

Cost Comparison

How much do Nexium and Prilosec cost?

One of the significant differences between Nexium and Prilosec is the cost of the medications. Nexium was only available with a prescription until 2014, and that too at a high price. However, it is now available as an over-the-counter drug at almost the same price as Prilosec. It is important to note that generic Nexium might be more affordable than over-the-counter Prilosec. Then again, per prescription cost of both significantly differ.

40 mg (30 capsules) Nexium is available at $15.50, while 40 mg (30 capsules) Prilosec is available at $16.50.

The average cost per prescription of Nexium is around $203.93, and per therapy day is around $4.33. On the other hand, the average cost per prescription of Prilosec is around $16.18, and per therapy day is around $0.32.

The popularity of Nexium and Prilosec

Based on the massive price difference, Prilosec is a more popular drug than Nexium and has been ranked as the 8th top drug in the US. In comparison, Nexium has been ranked as the 122 top drugs in the US. There has also been a significant decline in the rate of prescription of Nexium from 2013 to 2020 as compared to the study rate of prescription of Prilosec.



Many clinicians and scientists have agreed that Prilosec and Nexium have similar overall effects and that there aren't any major differences between the two in treating heartburn. Both drugs are PPIs and work by controlling stomach acid production. A higher amount of stomach acid leads to GERD and other disorders often treated with PPIs, particularly Prilosec, and Nexium.

While both drugs have an almost identical chemical makeup, Nexium has been found to be slightly more effective than Prilosec. However, there are higher numbers of prescriptions for Prilosec since it is considerably more affordable.