Yet another study is raising questions about the long-term safety of Nexium and other proton pump inhibitors. This time, scientists with the Houston Methodist Research Institute are reporting that use of the popular heart burn drugs could cause blood vessels to age faster, which could explain why some other studies have suggested that the medications might harm the heart and kidneys.
“Our finding that the lining of blood vessels is impaired by proton pump inhibitors is a unifying mechanism for the reports that PPI users are at increased risk for heart attack, stroke and renal failure,” Dr. John Cooke, the study’s senior author said in a press release announcing the findings.
The study examined cultures of endothelial cells, which line the walls of blood vessels. Each day, and for an extended period of time, the cultures were exposed to doses of Nexium similar to what a patient would typically take. The outcome of the experiment indicated that Nexium impaired acid production by lysosomes, which typically clear waste products from the cells. The resulting waste build-up caused the endothelial cells to age rapidly, which could interfere with their ability to protect the blood vessels.
Similar damage was not seen in cultured endothelial cells that were exposed to H2 blockers, a class of heart burn drugs that includes Zantac and Tagamet.
Proton pump inhibitors include Nexium, Prilosec, Pepcid and a number of other prescription medications. Over-the-counter versions, including Nexium 24HR, Prilosec OTC and Pepcid 24HR, are also available. They work by blocking acid-producing cells in the lining of the stomach. But the results of this study suggest that proton pump inhibitors might also inhibit acid-reducing cells elsewhere in the body.
It is estimated that some 15 million Americans were prescribed a proton pump inhibitor in 2013. Due to their widespread use, most people consider these drugs to be extremely safe. However, they have been associated with a number of serious side effects including C. diff infections, B12 deficiency and low magnesium levels. The proliferation of over-the-counter medications has also raised concern that many people are using the drugs for extended periods of time, even though they are only recommended for a short course of treatment.
Most recently, research has pointed to a possible link between drugs like Nexium and kidney failure. In April, researchers writing in the Journal of the American Society of Nephrology reported that long-term users of proton pump inhibitors may be 96% more likely to develop kidney failure and 28% more likely to develop chronic kidney disease compared to patients using another class of heartburn drugs called H2-blockers. Research that appeared in JAMA Internal Medicine in January also suggested that proton pump inhibitors might increase the risk of chronic kidney disease by as much as 50%.