In most mass tort cases there is a distinct injury or injuries established from the onset of litigation; however, this is not the case with the Proton Pump Inhibitor (PPI) lawsuits. The multidistrict litigation (MDL) was established on Aug. 2, 2017, and all cases were transferred to the federal district court in New Jersey. Attorneys must be armed with a sufficient organizational system to keep the many injuries, drugs and deadlines clear from the beginning.

This litigation is unique in that it has many moving parts. One client could have used a variation of at least seven different brand names of the PPI drug, prescribed or over-the-counter, with multiple injuries, each case with its own set of circumstances. Another moving part involves knowledge of the strengths and weaknesses in a case, which requires medical research. When filing a PPI case, not only must an attorney determine there was PPI use but he must also be able to determine whether there is evidence of a kidney injury. Therefore, when deciding whether to take a case, attorneys must be well versed with not only the basic requirements of use and injury, but also the research relating to and the science behind each ailment. Organization and medical summary are key for each individual case.

It is important to first note that the U.S. Food and Drug Administration (FDA) approved PPIs, for the short-term treatment of gastroesophageal reflux disease (GERD), active duodenal ulcers, severe erosive esophagitis, and pathologic hyperesecretory conditions—producing excess stomach acid. However, PPIs are commonly prescribed to treat acid reflux, and often used long-term. Manufacturers behind pharmaceutical medications such as Prevacid, Nexium, Protonix, Dexilant, Aciphex, Prilosec, PrevPac, Prevacid 24 Hour, Nexium 24 Hour, and Prilosec OTC, have been named in PPI complaints for concealing knowledge that kidney injuries can result after use of these PPIs. PPIs work by irreversibly blocking an enzyme in the body commonly referred to as a gastric proton pump to inhibit gastric acid secretion, see Shin, Jai Moo, “Pharmacology of Proton Pump Inhibitors“ Curr Gastroenterol. Rep. 528-34 (Dec. 2008). After PPIs block acid secretion, the effect can have unforeseen consequences. To have a better understanding, one who works in PPI litigation must keep up with the relevant science and literature as it touches upon gastroenterology and nephrology, just to name a few areas of focus.

PPI Use and Serious Ailments

The master complaint filed in the MDL alleges PPI use causes kidney-related injuries, such as chronic kidney disease (CKD), acute kidney injury, end stage renal disease (ESRD), and acute interstitial nephritis. There have been numerous case reports and studies published since 1992 documenting the association between PPIs and serious kidney injuries. In 1992, Ruffenach published a case report believed to be the first to find an association between Omeprazole and acute interstitial nephritis, see Ruffenbach, Stephen, “Acute Interstitial Nephritis Due to Omeprazole,” 93 The Am. J. Med. 472-73 (Oct. 1992). In 2006, Geevasinga published an article concluding that PPI-induced acute interstitial nephritis is likely to become more frequent, an there is now evidence to suggest a class effect incriminating PPIs, Geevasinga, Nimeshan, “Proton Pump Inhibitors and Acute Interstitial Nephritis,” Clin. Gastro. And Hepatology 597-604 (2006). Fast forward to 2016 and additional research revealed a connection between an increased risk of chronic kidney disease associated with the use of PPIs, see Lazarus, Benjamin, “Proton Pump Inhibitor Use and Risk of Chronic Kidney Disease,” JAMA Intern. Med. (Feb. 1, 2016); Xie, Yan, “Long-Term Kidney Outcomes Among Users of Proton Pump inhibitors Without Intervening Acute Kidney Injury,“91 Kidney Int'l 1482-94 (June 2017), publ. online Feb. 2017. Patients' lab work will reveal high levels of creatinine and lower levels of estimated glomerular filtration rate (eGFR) to indicate whether a patient has developed CKD that may progress to ESRD and the use of dialysis treatment depending on a lowered eGFR. However, these medications have also been associated with a multitude of other serious ailments.

In October 2017, one such study concluded that the long-term use of PPIs was associated with a diagnosis of gastric cancer, see Cheung, Ka Shing, “Long-Term Proton Pump Inhibitors and Risk of Gastric Cancer Development after Treatment for Helicobacter Pylori: A population-Based Study,” Gut 2018; 67: 28-35 (Oct. 31, 2017). There was a 2.4-fold increase in gastric cancer risk in H.pylori-infected subjects who had received eradication therapy, i.e. PPI therapy. The risk of gastric cancer increases with the dose and duration of PPI use.

Gastric cancer is one of the leading causes of cancer-related deaths in the world; however, the incidence and mortality of gastric cancer has fallen dramatically in the United States and elsewhere over the past several decades. Use of PPIs after H.Pylori eradication for long-term use more than doubles the risk of gastric cancer, while the use of H2 blockers, another class of acid reducers, did not increase this risk.

In February 2018, a study in Sweden found an associated link between long-term use of PPIs and an increased risk of esophageal cancer, see Brusselaers, Nele, “Maintenance Proton Pump Inhibition Therapy and Risk of Oesophageal Cancer,“ 53 Cancer Epidemiology 172-77 (2018). The most common predisposition for esophageal cancer is GERD, and it is the sixth most common form of cancer deaths worldwide. In August 2018, another study found PPIs are associated with an increased risk of hepatocellular carcinoma, the most common form of liver cancer after long-term use of PPIs, Shao, YJ, “Association Between Proton Pump Inhibitors and the Risk of Hepatocellular Carcinoma,” Ailment Pharmacol. Ther. (Aug. 2018). A team from the University of California San Diego School of Medicine found the absence of gastric acid promotes the growth of Enterococcus bacteria in the intestine, which then moves to the liver where they exacerbate inflammation and worsen to chronic liver disease. The study leader noted that gastric acid is used to kill ingested microbes and taking medications to suppress gastric acid secretion can change the composition of the gut microbiome, and in this case, promote the growth of such bacteria that causes liver disease.

The first prescription brand proton pump inhibitor was approved for use in 1989. The first over-the-counter PPI was approved in 2003. PPIs are among the top 10 classes of prescribed medications in the United States with at least $13.5 billion in U.S. sales, see Durand, Cheryl, “Proton Pump Inhibitor Use in Hospitalized Patients: Is Overutlization Becoming a Problem?“ 5 Clin. Med. Insights Gastroenterol. 65-76 (Oct. 15, 2012).

The first bellwether trial is currently set for September 2020.

Caitlin Wilenchik is an associate at Anapol Weiss working with the firm's mass tort team. She is a graduate of George Washington University Law School and is barred to practice in Pennsylvania.