Ab0125 Gout Patients With Chronic Kidney Disease Require Lower Febuxostat Doses to Achieve Target Serum Urate Levels: Results From the Ultra Registry

Background: Chronic kidney disease (CKD) is frequently observed in patients with gout due to impaired excretion of serum urate (SU). Febuxostat is a xanthine oxidase inhibitor developed as an alternative to allopurinol for treating hyperuricemia in patients with gout. Febuxostat was approved without dose adjustment for patients with mild-to-moderate renal impairment (estimated glomerular filtration rate [eGFR] of 30 to 90 mL/min/1.73m2). Objectives: The aim of this study was to determine the febuxostat dose requirement in gout patients with CKD who achieve target SU levels. Methods: This study performed on patients enrolled in Urate Lowering TheRApy in gout (ULTRA) registry. The ULTRA registry is an established cohort that prospectively enrolls Korean patients with gout treated in multiple centers nationwide since September 2021. A total of 342 gout patients were enrolled in this registry and 95 patients who followed up for one year were analyzed in this study. Study subjects were categorized into normal and CKD group by the estimated glomerular filtration rate as a 60 ml/min/1.73m². The dose of febuxostat or allopurinol in patients who achieved the SU target (< 6 mg/dL) was defined as the average daily dosage at the time of SU target achievement. Results: Seventy-one (74.7%) patients and twenty-four (25.3%) patients were allocated into normal and CKD group. Febuxostat was used in 65.2% of normal and 77.3% of CKD group. The rate of patients who achieved SU target was 67.6% in normal and 66.7% in CKD group (P=1.0). Although the mean febuxostat dose at baseline was not different among the patients with achieved SU target at one year (41.8 ± 14.5 mg vs. 42.4 ± 19.9 mg in normal and CKD group, P=0.914), after one year the febuxostat dose in CKD group was significantly lower than that in normal group (40.0 ± 18.2 mg vs. 53.7 ± 19.8 mg, P=0.015). Conclusion: Among patients who achieved SU target, those with CKD required a lower febuxostat dose to achieve the target SU level compared to patients with normal kidney function. REFERENCES: [1] Moon KW, el al. The aftermath of urate-lowering TheRApy in gout (ULTRA) registry: The first prospective observational multicenter cohort of Korean patients with gout. Int. J. Rheum. Dis. 2023;26:1015–1018. Acknowledgements: NIL. Disclosure of Interests: None declared.