Up-titration of allopurinol in patients with gout

Objectives: European League against Rheumatism ( EULAR ) gout management guidelines recommend achieving a target urate level < 6.0 mg/dL ( < 357 µmol/L ). Allopurinol is the most widely used urate-lowering therapy; however, many gout patients who are prescribed allopurinol do not have urate levels optimally controlled. The objective of this analysis was to review the efficacy and tolerability of allopurinol up-titration in achieving the EULAR target levels. Method: The Febuxostat versus Allopurinol Streamlined Trial ( FAST ) is an ongoing multi-centre study comparing the cardiovascular safety of febuxostat and allopurinol ( target recruitment: 5706 patients ). Recruited patients were already taking allopurinol and the protocol required up-titration of daily allopurinol dose, in 100 mg increments, to achieve the EULAR urate target level prior to randomisation. We reviewed pre-randomisation data from the first 400 recruited and subsequently randomised FAST patients. Results: Of 400 patients, 144 ( 36% ) had urate levels ≥357 µmol/L at screening and required allopurinol up-titration. Higher urate levels were significantly associated with lower allopurinol dose, male sex, increased BMI, increased alcohol intake and diuretic use. Mean fall in urate levels after a single 100-mg dose increase was 71 µmol/L. The number of up-titrations required ranged from one to five ( median = 1 ) with 65% of patients controlled after one 100-mg up-titration. Overall, 97% of up-titrated patients achieved target urate levels with median final allopurinol dose of 300 mg daily. Side effects and complications of up-titration were minimal. Conclusion: Overall, 36% of FAST patients were not at target urate levels and required up-titration. Allopurinol up-titration was effective in achieving urate target levels and was generally well tolerated by patients.