Proton pump inhibitor‐induced acute interstitial nephritis

What is already known about this subject • In several case reports the use of omeprazole has been associated with interstitial nephritis. • Recently there have been reports linking other proton pump inhibitors (PPIs) with interstitial nephritis. What this study adds • We present supplementary cases received by the Netherlands Pharmacovigilance Centre Lareb, concerning interstitial nephritis in users of PPIs including omeprazole, pantoprazole and rabeprazole. • In this case series seven patients are presented. In six cases they recovered spontaneously after cessation of the PPI, in one case the patient recovered after treatment with a corticosteroid. • Further support for this association comes from the worldwide adverse drug reaction database of the World Health Organization. • This report shows that interstitial nephritis can occur with all PPIs. Health professionals should be aware of this potential serious adverse drug reaction. Aim To investigate the association between the use of proton pump inhibitors (PPIs) and acute interstitial nephritis (AIN). Methods The Netherlands Pharmacovigilance Centre Lareb received seven case reports of AIN induced by various PPIs. In five of the reports it was mentioned that the diagnosis was confirmed by a renal biopsy. Results The time to onset varied between hours to 4 months. In all cases but one the patient spontaneously recovered after withdrawal of the offending agent. In one case the patient received treatment with prednisolone and recovered. In one patient a rechallenge was done 9 days after the initial event. Within 12 h of re‐exposure the patient developed symptoms of AIN. Conclusions The mechanism of drug‐induced AIN is unknown, but an immunological mechanism is suspected. Our reports show no relation between dosage, latency, time to recovery, age or gender, supporting the hypothesis that the aetiology of AIN is immunological. Lareb has received reports of AIN with the use of omeprazole, pantoprazole and rabeprazole. This shows that AIN is a complication associated with the whole group of PPIs and not only omeprazole. It is important for health professionals to be aware of this adverse drug reaction, because an accurate and timely diagnosis and withdrawal of the offending drug can prevent potentially life‐threatening renal failure.