Side Effects of Prilosec, Nexium, Other Heartburn Drugs May Increase Risk of Infections: Study

New research suggests that popular heartburn drugs like Prilosec and Nexium may disrupt the delicate balance of bacteria in your guts, leaving you defenseless against gastrointestinal infections and other problems. 

In a study published in the medical journal Microbiome on November 24, researchers from the Mayo Clinic found that long-term use of a class of drugs known as proton pump inhibitors (PPIs) can reduce the microbial diversity in your body; essentially destroying the “good” bacteria in your digestive system that helps it to both function properly and fight off Clostridium difficile infections (CDIs).

PPIs reduce the amount of acid in the stomach and are used to treat gastroesophageal reflux disease (GERD), as well as heartburn, ulcers in the stomach and small intestines, as well as inflammation of the esophagus. Drugs that belong to the class include AcipHex, Dexilant, Nexium, Prevacid, Prilosec (and generic omeprazole), Protonix, Vimovo and Zegerid.

The study involved nine test subjects who were randomly assigned either high or low doses of PPIs and tested over a period of about a month. Researchers found that use of both high and low dosages of medications like Nexium, Prilosec and Prevacid reduced the amount of gut bacteria to levels similar to those who were known to have CDI.

Once the use of the heartburn drugs was stopped, the bacteria began to recover.

“We conclude that decreases in observed species counts were reversible after cessation of PPI usage within 1 month,” the study’s authors concluded. “This finding may be a potential explanation for the association between prolonged PPI usage and CDI incidence.

CDIs can lead to Clostridium difficile-associated diarrhea (CDAD), causing persistent diarrhea, water stool, abdominal pain and fever. It can eventually lead to more severe intestinal problems if not treated in a timely manner.

The FDA first warned of the link between drugs like Nexium and Prilosec and CDIs in a drug safety communication in February 2012. The agency required new warnings be placed on the drugs at that time and warned doctors to be aware of the potential connection when presented with patients taking heartburn medications whose diarrhea did not improve.

The agency added further warnings in late October for CDAD and other health risks associated with the medications. The label changes also include new warnings about how long PPIs should be taken to treat gastroesophageal reflux disease (GERD), vitamin B 2 deficiency, and acute interstitial nephritis.

In 2010, the FDA required the manufacturers of all other proton pump inhibitor (PPI) medications to update the warning labels, adding information about a potential risk of fractures and bone problems from side effects of Prilosec, Nexium and other drugs in the same class.

That warning was updated again by the FDA in 2011, indicating that the risk of broken bones from Nexium appears to be linked to high doses of the medication used over long periods of time, which is exactly the kind of prescribing behavior the study found happens far too often.  Over-the-counter versions of the drug did not appear to be affected, according to federal drug regulators.

A number of former users who have suffered bone fractures are now pursuing a Nexium Lawsuit, alleging that AstraZeneca failed to adequately warn about the risks associated with long term use of the heartburn drug.