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Prilosec (Omeprazole)

People have been using Prilosec and its OTC variation to treat stomach acid problems since 1990. However, heartburn sufferers who turned to the drug for relief may experience cases of dementia, kidney disease and kidney failure, according to recent studies. Resulting lawsuits against AstraZeneca are only the latest in a long string of legal action over the drug.

Have you struggled with kidney problems after taking Prilosec?You might be entitled to compensation.

What is Prilosec?

Prilosec, also known generically as omeprazole, is a delayed-release prescription drug designed to treat symptoms of persistent heartburn. Consumer Reports published an article in 2012 recommending OTC Prilosec over other proton pump inhibitors as the best cost-effective choice for those struggling with heartburn.

Although it effectively treats heartburn, studies link Prilosec and other proton pump inhibitors to several dangerous health conditions such as dementia, kidney disease and kidney injury or failure.

Common Prilosec side effects include:

  • Headache
  • Acid regurgitation
  • Nausea, Vomiting & Stomach pain
  • Gastrointestinal Side Effects
  • Cold Symptoms
  • Constipation
  • Rash
  • Weakness or lack of energy
  • Back pain

Who Manufactures Prilosec?

AstraZeneca began producing Prilosec in 1989, lost patent protection for the drug in 2002 and one year later began producing an over-the-counter version. Prilosec OTC was the first proton pump inhibitor available without a prescription and is now sold in a regular or wildberry flavor.

Since its release, more than 27 million people have used Prilosec OTC to treat heartburn.

From 2003 – 2006, the U.S. Food and Drug Administration allowed AstraZeneca to produce Prilosec and Prilosec OTC without any competition. In 2008, AstraZeneca reapplied for approval of Prilosec with the FDA.

Prilosec sales have been declining in recent years. In 2013, AstraZeneca reported $486 million in the drug’s global sales, compared to $422 million in 2014 and $340 million in 2015.

AstraZeneca sells omeprazole in the United Kingdom, under the brand name Losec. A similar drug, known as Zegerid, uses the same active ingredient, omeprazole, combined with sodium bicarbonate, an antacid. Zegerid is manufactured by Salix Pharmaceuticals, Inc.

Prilosec Uses

GERD is the most common gastric problem Prilosec treats. People with GERD — also known as acid reflux disease — experience heartburn due to a malfunctioning muscle in the esophagus, the lower esophageal sphincter. This happens when acid moves past this muscle and into the esophagus, creating the painful sensation of heartburn. Stomach acid is corrosive and can lead to esophageal injuries if left untreated.

Hypersecretory conditions, such as Zollinger-Ellison syndrome, cause the body to overproduce certain substances. In the case of Zollinger-Ellison syndrome, a tumor or pre-cancerous pancreas causes overproduction of gastric acid that can lead to recurring peptic ulcers.

The FDA approved the prescription for use in both adults and children.

  • Gastric ulcers
  • Duodenal ulcers
  • Pylori infection
  • Heartburn
  • Gastroesophageal reflux disease (GERD)
  • Upper Gastrointestinal Bleeding
  • Erosive esophagitis
  • Pathological hypersecretory conditions

How Omeprazole Works

With a chemical structure that is similar to Nexium, Prilosec treats GERD and other gastric conditions by reducing the amount of acid in a person’s stomach. With less acid, it is less likely the fluid can reach the esophagus, damaging its tissue and causing heartburn.

Stomach cells called proton pumps produce stomach acid. This process naturally increases when a person eats because gastric acid digests food. Proton pump inhibitors like Prilosec slow down the pumps, reducing the production of acid and treating the symptoms of GERD.

Serious Prilosec Side Effects

Although patients who take Prilosec may experience relief from heartburn, they may also encounter side effects that threaten their health. Some are more dangerous than others. Researchers documented many Prilosec side effects during clinical trials and shortly after AstraZeneca released the drug. The company warns about these side effects on drug labels.

Two of the first severe side effects listed on the Prilosec medication guide are diarrhea — which may be caused by an intestinal infection — and bone fractures of the hip, wrist or spine. Research also shows Prilosec can cause an allergic reaction in some patients.

In 2015 and 2016 several studies also linked proton pump inhibitors like Prilosec to adverse health conditions like kidney disease, kidney failure and dementia. These conditions are not listed on prescription omeprazole labels and pose a serious risk to long-term Prilosec users.

Symptoms of these allergic reactions include:

  • Anaphylactic shock
  • Severe swelling, typically of the eyes, lips, hands or feet
  • Narrowing airway, which can cause wheezing and coughing
  • Interstitial nephritis, or temporary kidney problems due to swollen tubules
  • Hives
  • Fever
  • Pain
  • Fatigue
  • Malaise

Kidney Disease

In 2016, one study found people taking proton pump inhibitors like Prilosec were nearly 30 percent more at risk for developing kidney disease than someone who did not take the drugs. The study compared patients who took proton pump inhibitors with those who took histamine H2 receptor blockers. Both types of drugs suppress stomach acid.

The study tracked 170,000 proton pump inhibitor and 20,000 H2 blocker patients over the course of five years. Of the proton pump inhibitor patients, 15 percent developed kidney disease. Of the H2 blocker patients, 11 percent developed kidney disease.

After adjusting the data for additional factors, the researchers determined people who used proton pump inhibitors like Prilosec were 28 percent more likely to develop a kidney disease. In addition, 0.2 percent of patients between both groups developed end-stage kidney failure, and the researchers determined those on proton pump inhibitors were 96 percent more at risk.

Kidney Injury

Prilosec studies show the medication can cause kidney injury in those who have an allergic reaction to the drug. However, in April 2015 scientists released a new study that showed the correlation between proton pump inhibitors like Prilosec and the development of kidney injury in older patients.

Kidney injury includes the sudden loss of kidney function. In some cases, it leads to kidney failure and the need for dialysis or kidney transplant.

The data revealed those who took proton pump inhibitors like Prilosec had double the risk of those who did not take the drug of developing acute kidney injury.

The study examined more than 600,000 patients who were 66 years or older. Some patients took proton pump inhibitors, and an equal number in a second group served as the control. While some members of the control group did develop kidney injury — 5.46 percent — the numbers in the group taking the drugs were more than double — 13.49 percent.


In February 2016, European researchers revealed data that showed patients taking proton pump inhibitors like Prilosec were nearly twice as likely to develop dementia as those who didn’t. Severe memory loss is the most distinct characteristic of dementia.

In the study of roughly 73,600 individuals, around 29,500 developed dementia and were evaluated as part of the findings. Of the whole group, around 2,900 were regular users of proton pump inhibitors. The remaining 70,700 patients did not receive the medication.

Using the data, the scientists concluded those taking proton pump inhibitors had a 44 percent increased risk of developing dementia during the study, which lasted from 2004 – 2011.

Prilosec Respiratory Events

One clinical trial showed pediatric patients were more likely to experience three new side effects separate from those adults experienced. The trial surveyed the children in separate groups, aged 1 – 2 years and 2 – 16 years.

It found the most frequently reported Prilosec side effect between both groups was “adverse reactions of the respiratory system.” The 1 – 2 age group also commonly experienced fevers, and the 2 – 16 age group experienced accidental injuries.

Respiratory Effects Fever Accidental Injuries
1 – 2 years old 75% 33%
2 – 16 years old 18.5% 3.8%

Prilosec (Omeprazole) and Pregnancy Risks

Similar to those with GERD, pregnant women also regularly experience heartburn. During pregnancy, a woman’s body produces more progesterone, a hormone that controls muscle relaxation, which causes the lower esophageal sphincter to loosen and allows stomach acid to reach the esophagus. Many women experience these symptoms during the first trimester of pregnancy.

The FDA gave Prilosec a pregnancy category “C” rating, which means it is unknown whether the drug will harm an unborn baby if the mother consumes the medication during pregnancy.

When the FDA wrote the safety card for Prilosec in 2000, a medical professional noted the prescription had been linked to negative outcomes in animal studies — specifically in-utero deaths of rabbit fetuses and weight gain in rats after birth. However, the report also stated omeprazole does not affect fertility and is not teratogenic, meaning it does not cause birth defects.

Because of the “C” rating, many doctors recommend pregnant women use alternative heartburn medications with a “B” rating or higher.

Omeprazole can pass into breast milk, so many doctors recommend nursing mothers avoid taking it while breastfeeding.


Prilosec capsules are available in a variety of doses, ranging from 10 mg to 40 mg. Doctors prescribe once or twice daily dosages, and prescriptions vary from patient to patient based on their specific needs.

The dosage recommendations also vary based on a person’s condition.

The drug begins to take effect one hour after taking the medication and can last up to 72 hours. Patients should take Prilosec before eating.

Prilosec also comes in an over-the-counter form, Prilosec OTC. Doctors suggest this medication for people experiencing frequent heartburn that occurs more than two days per week. Prilosec OTC should be used once per day for 14 days. This treatment may be used once every four months.

Condition Recommended Dosage
Duodenal Ulcer 20 mg once daily for 4 weeks
H. pylori 20 mg, combined with antibiotics twice daily for 10 – 18 days
Gastric Ulcer 40 mg once daily for 4 – 8 weeks
Gastroesophageal Reflux Disease (GERD) 20 mg once daily for 4 – 8 weeks
Erosive Esophagitis 20 mg once daily for as long as clinically recommended
Pathalogical Hypersecretory Conditions 60 mg once daily for as long as clinically recommended

FDA Warning for Prilosec and Plavix

In November 2009, the FDA released a new safety warning cautioning patients from using the anti-clotting drug Plavix and Prilosec or Prilosec OTC together.

Blood clots often cause serious health conditions such as heart attack and stroke. Patients who are at risk of these conditions often take Plavix as an anti-clotting measure.

Data shows that when patients take the two drugs together Plavix is 50 percent less effective. This is because liver enzymes absorb Plavix, and Prilosec blocks the production of these enzymes. Research showed these results only occurred with the use of omeprazole and not all proton pump inhibitors.

Despite evidence of Prilosec's dangers, AstraZeneca continues to manufacture the drug and advertise to millions of television viewers with the popular Larry the Cable Guy commercials.

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