Allopurinol is started in a patient with recurrent gout and a serum urate of 9.8 mg/dL. Two weeks later he presents with an acute attack of gout despite good adherence. The most appropriate explanation and management step is:
- A Allopurinol failure; switch immediately to febuxostat at full dose
- B Mobilisation of urate from tissue stores as levels fall; continue allopurinol and cover with colchicine or an NSAID ✓
- C Paradoxical increase in xanthine oxidase activity; stop allopurinol permanently
- D Allergic interstitial nephritis from oxypurinol; add a corticosteroid and restart allopurinol after desensitisation
Correct answer: B. Mobilisation of urate from tissue stores as levels fall; continue allopurinol and cover with colchicine or an NSAID
Explanation
Falling serum urate destabilises monosodium urate crystals in tophi and joint deposits, shedding crystals into the synovium and triggering flares during the first months of therapy. This is expected and is not a reason to stop treatment. Standard practice is to continue the urate-lowering drug and provide flare prophylaxis with low-dose colchicine or an NSAID for three to six months. Switching agents does not prevent crystal mobilisation, and this presentation is unrelated to hypersensitivity.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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