Peptic Ulcer Medications Linked to Kidney Disease

Although they are revolutionary for the treatment of various gastric acid-related disorders, proton pump inhibitors (PPIs) may be linked to interstitial nephritis, according to research published March 19, 2014, in Kidney International.

Researchers from the University of Otago in New Zealand analyzed health and prescription data from 572,661 people of varying ages who were dispensed omeprazole, pantoprazole, or lansoprazole between 2005 and 2009. The researchers noted a difference between patients who were dispensed medication and prescribed it, and although there was no way to test adherence levels, they estimated high adherence.

The investigators excluded patients with pre-existing or history of kidney disease, but they considered other factors, such as age, sex, and other medical conditions and prescription drugs. Only patients whose interstitial nephritis was severe enough to cause hospitalization or death were considered, though no fatal cases were found.

After exclusions, the investigators found 72 validated candidates with interstitial nephritis — 46 of which were definite cases, or histologically confirmed, while 26 were probable cases, or confirmed by discharge letter — and 719 matched controls (460 definite and 259 probable).

Recent use of PPIs was associated with elevated risk of interstitial nephritis; however, after a secondary analysis, the researchers found no conclusive evidence of a dose-response relationship or duration effect.

“We found that the current use of the PPIs omeprazole, pantoprazole, or lansoprazole was associated with a significantly increased risk of acute interstitial nephritis resulting in hospitalization compared with past use,” the authors wrote.

In a press release, study co-author Lianne Parkin, PhD, said “the excess risk of interstitial nephritis we observed in current users of PPIs, although low in absolute terms, is important from a population perspective as PPIs are one of the most widely prescribed groups of drug.”

“Although the PPIs included in our study are extremely safe for the vast majority of users, it is important for prescribers to be aware of this increased risk of interstitial nephritis, and for patients to seek appropriate advice before using these medicines,” Parkin said.

The authors advised primary care physicians to research the risks before prescribing PPIs to patients suffering from heartburn and/or peptic ulcers, since the medications are not without risk. They also warned against the large number of patients buying over-the-counter PPIs — especially in the United States, where they may be inappropriately used.