Urate Lowering Efficacy of Febuxostat Versus Allopurinol in Hyperuricemic Patients with Gout

Background: The prescribed maximum dose of allopurinol is 300 mg/day to maintain a serum uric acid (sUA) concentration of < 6.0 mg/dl. However, increasing evidence shows that 300 mg dose is ineffective in achieving the target sUA level, limiting allopurinol's use in certain subsets of patients who are intolerant to allopurinol such as patients with chronic kidney disease, with multiple comorbidities and elderly patients. Objective: To determine the efficacy and safety of febuxostat compared with allopurinol in lowering sUA level in patients with hyperuricemia in gout with a baseline sUA ≥ 8 mg/ dl. Data sources: Electronic searches through COCHRANE, EMBASE, PUBMED, and Manual Search. Search terms included the following: febuxostat, allopurinol, hyperuricemia, gout. Study Selection: Randomized, double-blinded, parallelgroup clinical trials with meta-analysis quality scale of A-B were included. Intervention included administration of febuxostat and allopurinol in determined dosages and duration in each study. Analysis: All outcomes were examined using the random effects model. Dichotomous data were analyzed by calculating the odds ratio, with 95% confidence interval and a significant p value of 0.1 was used. Results: Pooled data showed significant decrease in sUA level from baseline with febuxostat 80 mg than with allopurinol with OR 0.31 (95% CI, 0.24-0.39, p = 0.00001). The risk of developing any adverse event with allopurinol is greater compared to febuxostat with RR 0.90 (95% CI, 0.84-0.96, p = 0.002). Conclusion: Febuxostat has significant urate lowering efficacy than allopurinol, and in patients with renal impairment without requiring dose adjustment, with lower incidence of any adverse events. However, elevated liver enzymes brought about by febuxostat were noted. Keywords: Allopurinol, Febuxsostat, serum uric acid, hyperuricemia, gout Abstract Background of the Stud