Should allopurinol be continued in a patient with gout who is started on colchicine for a gout flare?

Continue Allopurinol During Gout Flares

Yes, absolutely continue allopurinol when starting colchicine for a gout flare. The 2020 American College of Rheumatology guidelines explicitly recommend against stopping urate-lowering therapy (ULT) during acute flares 1.

Key Management Principles

Continue Allopurinol Without Interruption

• Once allopurinol is started, it should be continued indefinitely to maintain serum urate below 6 mg/dL, regardless of acute flare activity 1.
• The ACR conditionally recommends continuing ULT indefinitely over stopping ULT 1.
• Stopping allopurinol during a flare can cause further fluctuations in serum urate levels, which paradoxically triggers more flares 2.

Add Colchicine as Prophylaxis and Flare Treatment

• Colchicine serves dual purposes: treating the acute flare AND preventing future flares during the critical early months of allopurinol therapy 1, 2, 3.
• The FDA label for allopurinol explicitly states that "maintenance doses of colchicine generally should be given prophylactically when allopurinol tablets are begun" 2.
• For acute flare treatment: Give colchicine 1.2 mg at first sign of flare, followed by 0.6 mg one hour later, then wait 12 hours before resuming prophylactic dosing 3.

Duration of Colchicine Prophylaxis

• Continue colchicine prophylaxis for 3-6 months minimum after starting or adjusting allopurinol, with ongoing evaluation 1.
• The ACR strongly recommends continuing prophylaxis for 3-6 months rather than less than 3 months 1.
• Evidence shows colchicine reduces both frequency (0.52 vs 2.91 flares) and severity of acute flares when initiating allopurinol 4.
• If flares continue beyond 6 months, extend prophylaxis as needed, particularly if serum urate remains above target 1, 5.

Why This Approach Works

The Mobilization Phenomenon

• Initiating or adjusting allopurinol causes mobilization of urate from tissue deposits, creating temporary fluctuations in serum urate that trigger flares 2.
• This paradoxical increase in flare frequency occurs even when serum urate levels are normalizing 2.
• Continuing allopurinol through flares allows steady depletion of the total body urate pool, which takes several months 2.

Evidence Supporting Continuation

• A controlled trial demonstrated that colchicine prophylaxis during allopurinol initiation significantly reduces flare frequency, severity, and likelihood of recurrent flares over 6 months 4.
• The ACR guidelines conditionally recommend starting ULT during a gout flare over waiting until after flare resolution, emphasizing that continuation doesn't worsen or prolong flares 1.

Common Pitfalls to Avoid

• Never stop allopurinol during an acute flare - this creates more urate fluctuations and perpetuates the flare cycle 1.
• Don't use inadequate prophylaxis duration - stopping colchicine before 3 months is associated with breakthrough flares 1.
• Monitor for drug interactions - approximately 21% of patients on colchicine prophylaxis are also taking statins, which can increase adverse event risk 6.
• Adjust colchicine dose in renal impairment - patients with CKD stage 3 may need dose reduction to avoid toxicity 7, 6.

Dosing Specifics

Allopurinol Management

• Continue current allopurinol dose without interruption 1.
• If not yet at target serum urate (<6 mg/dL), continue dose titration as planned 1.

Colchicine Dosing

• For prophylaxis: 0.6 mg once or twice daily (maximum 1.2 mg/day) 3.
• For acute flare treatment while on prophylaxis: 1.2 mg at flare onset, then 0.6 mg one hour later; wait 12 hours before resuming prophylactic dose 3.