We are convinced that proton pump inhibitors have now been associated with acute interstitial nephritis. Perhaps the mass use of these agents in themedicine world has led to a sore of cases of AKI from AIN. The New Zealandnephrologists took it a step further and have conducted the largest study to dateon looking at AIN from PPIs. They did a nested case control study using national health and drug dispensing data from NZ to estimate the relative and absolute risk of AIN resulting in hospitalization or death from proton pump inhibitors. This was published in KI March 2014.
1. They identified close to 800,000 patients from the collection that had one course of PPI. Subsequently they studied close to 600,000 patients from 2005-2009. Cases of first diagnosis of AIN were done by hospital discharge summaries and renal histology in some cases. Ten controls were matched for each case they found. They identified 1164 patients as cases with the AIN diagnosis from PPI.
2. The cases and controls were equally matched.
3. The most common PPI in both cohorts was Omeprazole followed by pantoprozole and then lansoprazole.
4. The unadjusted matched odds ratio for was 5.16 for current vs past use of PPI. The crude incidence rates in 100,000person years was 11.98 for current use. The current use of PPI was associated with significant risk of AIN resulting in hospitalization compared to past use.
5. Case control study; small number of cases for overall population but still interesting. Other drug confounders? Age and sex confounders or other medical conditions- authors don’t think this explains it.
Have PPIs replaced antibiotics and NSAIDS as the most common cause of AIN now?