A study published in Circulation Research found that the popular heartburn medication Nexium speeds up the aging process in blood cells, which can lead to more severe health issues. Nexium is a Proton Pump Inhibitor (PPI) which helps reduce the amount of stomach acid rising up and damaging the esophagus.

The study found that Nexium accelerates the aging process and prevents healthy cells in the blood vessels from properly creating the coating that prevents blood from sticking to the inside of the blood vessels. Additionally, the study found that prolonged use of a PPI like Nexium hinders the ability of blood cells to clear waste.

Without the ability to clear blockages, damaged blood cells accumulate waste that accelerates the aging process. As blood vessels age, they can contribute to the development of conditions like chronic kidney disease and kidney failure.

The study was not without its limitations, it was performed in a laboratory setting rather than in a clinical trial, but the study’s lead author, John P. Cooke, MD, PhD, says it’s enough for the pharmaceutical industry to revisit the safety of using PPIs long-term.

AstraZeneca has been facing multiple allegations over its drug’s safety for several years. In 2014, the FDA updated the warning label on Nexium to include more side effects, including a vitamin B12 deficiency that increases the risk of bone fracture.

For many patients who have suffered chronic kidney disease and failure after taking Nexium, this study strengthens their claims that Nexium’s manufacturer, AstraZeneca, failed to warn patients of the risks associated with its PPI drug. This study will fuel the fire for many patients seeking to hold the company responsible.