LAUSR

BACKGROUND NSAID use is recommended to be avoided in kidney transplantation (KTX), with a paucity of studies assessing their safety within this population. This study aims to use a large cohort of Veterans Affairs (VA) KTX recipients to assess the risk of acute kidney injury (AKI) with NSAID use. METHODS This is a ten-year longitudinal cohort study of adult kidney transplant recipients retrospectively followed in the VA system from 2001-10 that assessed for risk of AKI with NSAID prescriptions. NSAID prescriptions, patient characteristics and eGFRs were abstracted from the VA comprehensive electronic health record. NSAID exposure was assessed by duration, dosage and type. AKI events were defined by ≥50% decrease in eGFR. Risk was estimated using longitudinal multivariable generalized logistic regression model. RESULTS 5,100 patients were included with a total of 29,980 years of follow up; 671 NSAID prescriptions in 273 (5.4%) patients (2.24 per 100 patient-years) with 472 (70%) high-dose were identified. High-dose NSAID prescriptions was associated with 2.83 (95% CI 1.55-5.19; p<0.001) higher odds of AKI events within a given year; low dose was not associated with AKI (OR 1.93 [0.95-6.02]; p=0.256). One 7-day NSAID course was associated with 5% higher odds of increasing AKI events, while chronic use (≥180 days) was associated with 3.25 (1.78-5.97; p<0.001) higher odds of AKI. CONCLUSIONS Prescriptions for NSAIDs were uncommon in this cohort, but was associated with a significant increase in the risk of AKI, which was impacted by higher NSAID dose and longer NSAID durations.