A new study suggests that taking proton pump inhibitors could increase the risk of contracting Clostridium difficile–associated diarrhea (CDAD) by as much as 80 percent. C. difficile represents an escalating threat to public health, and CDAD cost the US an estimated $3 billion in 2005.
Proton pump inhibitors, available by prescription and over-the-counter (OTC), work by reducing the amount of acid in the stomach, and are approved to treat conditions such as gastroesophageal reflux disease (GERD), stomach and small intestine ulcers, and inflammation of the esophagus. Prescription versions of the drugs include Nexium, Dexilant, Prilosec, Zegerid, Prevacid, Protonix, and Aciphex. OTC brands include Prilosec OTC, Zegerid OTC and Prevacid 24HR. Since their introduction in the 90s, proton pumps have ranked among the top selling drugs, with doctors writing 119 million prescriptions for them last year alone.
For this new study, researchers looked at data from 21 peer-reviewed published studies. The 7 cohort studies and 14 case-control studies included 133,054 individuals. Overall, there was a significant increase in the risk of CDAD in patients taking proton pump inhibitors (risk estimate, 1.80). The risk estimate in the case-control studies was 1.55 and in the cohort studies 2.07. The CDAD risk was significantly higher for patients taking proton pump inhibitors whether the types of studies were considered separately or as a whole.
According to one of the study’s authors, Dr. Sailajah Janarthanan of Wayne State University in Detroit, proton pump inhibitors have faced scrutiny for a possible association with CDAD, but results from previous studies have yielded mixed results. She noted that even a slight increase in the risk of CDAD conferred by these drugs will have major public health implications, considering how many people use proton pump inhibitors.
“Indiscriminate use of PPIs (proton pump inhibitors) without proper indication should be discouraged,” she wrote. “There is a real-time need for guidelines on the use of PPIs, especially in hospitals.”
Dr. Janarthanan and her colleagues did note that the studies they reviewed were limited by the lack of randomized, controlled trials, and that the impact of proton pump inhibitors on CDAD remains controversial.