Introduction: The purpose of this study was to describe the local experience in terms of drug efficacy and safety using a new xanthine oxidase inhibitor, febuxostat, as a second-line urate lowering therapy (ULT) in gout patients with normal renal function and chronic kidney disease.
Methods: This cross-sectional study included all gout patients who attended the rheumatology clinic from January 2013 to June 2018 and had received febuxostat as a second-line ULT. Analysis focused on the proportion of gout patients who achieved target serum urate (sUA) of <360 μmol/L, duration taken to achieve target sUA, and febuxostat dosage at achievement of target sUA. Safety assessments included comparison of serum creatinine, estimated glomerular filtration rate (eGFR), and serum alanine aminotransferase (ALT) at baseline, at achievement of target sUA, and at 12-monthly intervals.
Results: Majority (90.9%) of patients achieved target sUA. Median duration required to achieve target sUA was 5.5 months with IQR (interquartile range) of 8.5. Five (22.7%) patients achieved target sUA within one month of therapy with febuxostat 40 mg per day. Eleven (55%) patients achieved target sUA within six months and 16 (80%) by 12 months. Equal proportion of patients achieved target sUA with febuxostat 40 mg per day and 80 mg per day, respectively. There was no significant difference in the changes in serum creatinine level, eGFR and ALT from baseline and at achievement of target sUA, nor at 12-monthly intervals throughout the duration of febuxostat therapy. Apart from three patients who developed hypersensitivity reactions to febuxostat, no other adverse events were reported.
Conclusion: A significant proportion of gout patients with CKD managed to achieve target sUA with a lower dose of febuxostat at 40 mg per day and it is reasonable to maintain this dose for up to six months before considering dose escalation.