AstraZeneca may be facing more lawsuits alleging that Nexium, a medication used to treat acid reflux and heartburn, led to kidney damage. Newly filed cases allege that the company failed to disclose the risk of kidney side effects to patients or the medical community. Nexium is part of a class of medications known as proton pump inhibitors, which also includes Prevacid and Prilosec. PPIs work by reducing the amount of acid produced by the stomach.
Court documents indicate that a lawsuit was recently filed on behalf of an Illinois man. He says he began taking Nexium under the direction of his physician for many years. He suffered chronic kidney disease, in which he slowly lost kidney function, and alleges that Nexium was a contributing factor. The lawsuit cites hundreds of adverse event reports submitted to the U.S. Food and Drug Administration (FDA) regarding Nexium.
AstraZeneca denies these types of allegations. “AstraZeneca is confident in the safety and efficacy of Nexium and intends to vigorously defend this lawsuit.” the company stated.
Plaintiffs in the litigation cite two studies published this year linking PPIs to an increased risk of kidney damage. One study found that PPI users were 20 to 50 percent more likely to suffer chronic kidney disease compared to non-PPI users. The researchers also found that the risk was higher among individuals who took higher doses; a twice-daily dose was linked to a 46 percent increased risk while a once-daily dose was associated with a 15 percent increased risk. The findings were published in the journal JAMA Internal Medicine this past January.
Another study, published April in the American Society of Nephrology, found that PPI use was linked to a higher risk of chronic kidney disease compared to a different class of heartburn medications, known as H2 receptor blockers. Researchers found that among 170,000 new PPI users,15 percent developed chronic kidney disease compared to 11 percent of 20,000 new H2 receptor blocker users. Overall, this results in a 28 percent increased risk with PPI use, authors said. PPI use was also linked to a 96 percent increased risk of end-stage renal failure, although this only occurred in a handful of patients.
Both studies are correlational. The findings only point to an association; they do not prove that PPIs cause kidney damage.