A 55-year-old man with tophaceous gout has serum urate of 9.8 mg/dL on allopurinol 300 mg/day and is intolerant of higher doses due to skin rash. Which agent is most appropriate to lower urate to target (<5 mg/dL)?
- A Probenecid
- B Colchicine
- C Febuxostat ✓
- D Rasburicase
Correct answer: C. Febuxostat
Explanation
Febuxostat is a non-purine selective xanthine oxidase inhibitor that is an effective alternative when allopurinol is contraindicated or not tolerated; it is structurally unrelated to allopurinol so cross-reactivity is minimal. The CONFIRMS trial demonstrated that febuxostat 80 mg is superior to allopurinol 300 mg in achieving serum urate <6 mg/dL. Probenecid (uricosuric) requires good renal function and is less effective with tophi. Colchicine treats acute flares but does not lower urate. Rasburicase is used for tumor lysis syndrome, not chronic gout.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.