Nexium and Prilosec belong to a class of heartburn drugs called Proton Pump Inhibitors (PPIs). Another class of heartburn drugs called H2-blockers include Zantac and Pepcid-AC.
The researchers analyzed data from the Department of Veterans Affairs on 125,596 new users of PPIs and 18,436 new users of H2-blockers. After five years of follow-up, the results were remarkable.
Nearly 10% of PPI users developed chronic kidney disease, but less than 50% of them had immediate symptoms of kidney injury, such as reduced urination, fatigue, or swollen legs and ankles.
According to lead researcher Dr. Ziyad Al-Aly of Washington University in St. Louis:
Our results indicate kidney problems can develop silently and gradually over time, eroding kidney function and leading to long-term kidney damage or even renal failure.”
The study is concerning because it means a lot of PPIs users have “silent” kidney disease that goes undiagnosed for years. Doctors should not rely on obvious symptoms to determine if a patient has kidney problems. By the time symptoms appear, the patient may have kidney failure (end-stage renal disease).
In contrast, 7.7% of people on H2-blockers developed chronic kidney disease and 1.3% developed kidney failure (end-stage renal disease). While H2-blockers are less powerful than PPIs, many studies show less risk to the kidneys.
The study was published on February 22 in the journal Kidney International.
This is not the first time heartburn drugs have been linked to kidney problems. Last year, a study published in JAMA by researchers at Johns Hopkins found a 20-50% increased risk of chronic kidney disease.
Nephritis (kidney inflammation) was first linked to PPIs in the 1990s, but drug-makers did not add it to the label until 2014. The first Nexium lawsuit was filed in May 2016 by a man who suffered kidney failure and needed a transplant. He accuses drug-makers of downplaying the risk.