P0578QUININE EXPOSURE AND THE RISK OF ACUTE KIDNEY INJURY: A POPULATION BASED OBSERVATIONAL STUDY OF OLDER PEOPLE

Abstract

Abstract Background and Aims Quinine can precipitate Acute Kidney Injury (AKI) by immune-mediated reactions. Cramps, for which quinine is traditionally prescribed, may be a symptom of conditions that are risk factors for AKI. The relationship between quinine and AKI at a population level is unclear. The aim of this study was to establish and quantify any observable association between the exposure to community prescriptions for quinine and AKI events in a population of older adults. Method We performed two observational studies of older adults (60+ years) who received quinine prescriptions in Tayside, Scotland, between January 2004 and December 2015. The first study was a retrospective longitudinal cohort study with the primary outcome AKI. Creatinine measurements less than seven days apart were grouped as episodes of care. Multivariable logistic regression was used to calculate odds ratios (OR) for AKI comparing between episodes with and without recent quinine exposure after adjustment for demographics, comorbidities and concomitant medications. A self-controlled case series (SCCS) was then conducted with follow-up divided into periods “on” and “off” quinine for the same individual, calculating incidence rate ratios (IRR) for AKI adjusting for age. Results The first study included 12,744 individuals who experienced 13,616 AKI events during cohort follow-up (crude incidence 12.5 per 100 person-years). Exposure to quinine before an episode of care was significantly associated with an increased probability of AKI (adjusted OR=1.27, 95% CI 1.21-1.33). The SCCS cohort included 5,907 people with quinine exposure with ≥1 AKI event. Exposure to quinine was associated with an increased relative incidence of AKI compared to unexposed periods (IRR=1.20, 95% CI 1.15-1.26), with the greatest risk observed within 30 days of quinine initiation (IRR=1.48, 95% CI 1.35-1.61). Conclusion Exposure to quinine in patients aged 60 years and over was associated with an increased risk of AKI, the incidence of which is unlikely to simply be explained be immune-mediated reactions only. Further research is required to determine exact reasons for the increased risk of AKI.