Lead study author Tony Antoniou, PhD, a researcher at the Institute for Clinical Evaluative Sciences and St. Michael's Hospital in Toronto, and colleagues conducted a population-based study involving 290,592 Ontario residents aged 66 years and older who initiated PPI therapy between April 1, 2002, and November 30, 2011. They used propensity score matching to establish a highly comparable reference group of control patients. The primary outcome was hospital admission with acute kidney injury within 120 days, and a secondary analysis examined acute interstitial nephritis. They used Cox proportional hazards regression to adjust for differences between groups.
The rates of acute kidney injury (13.49 v. 5.46 per 1,000 person-years, respectively; hazard ratio [HR] 2.52, 95% CI 2.27 to 2.79) and acute interstitial nephritis (0.32 vs. 0.11 per 1,000 person-years; HR 3.00, 95% CI 1.47 to 6.14) were higher among patients given PPIs than among controls.
“These are potentially reversible conditions that may not be readily attributed to drug treatment. Clinicians should maintain a high index of suspicion for these adverse effects among patients who are prescribed proton pump inhibitors,” Antoniou said.
“Although the absolute risk of acute kidney injury with proton pump inhibitors is low, these drugs are used by millions of people each year,” he said. “Our results underscore the importance of ongoing efforts to curtail the indiscriminate use of these drugs. When these drugs are indicated, the need for their ongoing use should be periodically reappraised.”