When can a patient with gout take colchicine and when should allopurinol (xanthine oxidase inhibitor) be started?

When to Use Colchicine and When to Start Allopurinol in Gout

Colchicine should be started immediately at the first sign of an acute gout flare (within 36 hours of symptom onset), while allopurinol can be initiated during the acute attack or immediately after, with mandatory colchicine prophylaxis continued for at least 6 months. 1, 2, 3, 4

Colchicine for Acute Gout Flares

Timing and Dosing

• Start colchicine within 36 hours of symptom onset - effectiveness drops dramatically beyond this window 1, 2, 5
• The optimal window is within 12 hours of symptom onset for maximum efficacy 1
• Dosing regimen: 1.2 mg at first sign of flare, followed by 0.6 mg one hour later (total 1.8 mg over one hour) 1, 2, 3
• After the initial loading dose, wait 12 hours, then continue 0.6 mg once or twice daily until the attack completely resolves 1, 2

Critical Contraindications

• Absolute contraindication: Severe renal impairment (GFR <30 mL/min or CrCl <30 mL/min) - avoid colchicine entirely 1, 5
• Absolute contraindication: Concurrent use of strong CYP3A4 or P-glycoprotein inhibitors (clarithromycin, cyclosporine, ketoconazole, ritonavir) in patients with renal or hepatic impairment 1, 2, 3
• For dialysis patients, give only a single 0.6 mg dose and do not repeat for two weeks 5

Alternative Options if Colchicine Contraindicated

• NSAIDs at full FDA-approved doses (naproxen, indomethacin, sulindac) until complete resolution 1, 5
• Oral corticosteroids: prednisone 0.5 mg/kg/day (or 30-35 mg/day) for 5-10 days, then stop or taper over 7-10 days 1, 5
• Intra-articular corticosteroid injection for monoarticular involvement 1, 5

When to Start Allopurinol

Timing Relative to Acute Flare

• Allopurinol can be started during an acute gout attack - this does not prolong the attack when adequate anti-inflammatory prophylaxis is provided 4, 6
• The FDA label explicitly states that colchicine prophylaxis "generally should be given prophylactically when allopurinol tablets are begun" 4
• A randomized controlled trial demonstrated that initiating allopurinol during acute gout (with appropriate anti-inflammatory therapy) did not prolong attack duration (15.4 vs 13.4 days, p=0.5) 6

Starting Dose and Titration

• Start with 100 mg daily and increase at weekly intervals by 100 mg until serum uric acid reaches ≤6 mg/dL 4
• Maximum dose is 800 mg per day 4
• Lower starting doses are required for patients with decreased renal function 4

Mandatory Colchicine Prophylaxis with Allopurinol

Prophylactic Dosing

• Standard prophylactic dose: 0.6 mg once or twice daily 1, 2, 3
• Maximum prophylactic dose is 1.2 mg/day 3
• Start prophylaxis at the same time as or just prior to initiating allopurinol 2, 4

Duration of Prophylaxis

• Minimum duration: 6 months after starting urate-lowering therapy 1, 2
• Alternative stopping points: 3 months after achieving target serum urate if no tophi present, or 6 months after achieving target serum urate if tophi present 1, 2
• High-quality evidence from randomized trials demonstrates that colchicine prophylaxis significantly reduces acute flares during allopurinol initiation (0.52 vs 2.91 flares, p=0.008) 7

Rationale for Prophylaxis

• Allopurinol causes mobilization of urate from tissue deposits, leading to fluctuating serum uric acid levels that trigger acute flares 4
• Without prophylaxis, gout attacks increase in frequency during the early stages of allopurinol therapy 4
• Prophylaxis reduces both the frequency and severity of flares, and prevents recurrent attacks 7

Common Pitfalls to Avoid

• Do not delay colchicine beyond 36 hours of symptom onset - it becomes ineffective 1, 2
• Do not use the outdated high-dose colchicine regimen (0.5 mg every 2 hours) - it causes severe diarrhea without additional benefit 1
• Do not start allopurinol without colchicine prophylaxis - this is explicitly stated in FDA labeling and supported by high-quality evidence 4, 7
• Do not stop prophylaxis too early - continue for at least 6 months to prevent flare recurrence 1, 2
• Always calculate creatinine clearance before prescribing colchicine, especially in elderly patients 2
• Do not combine colchicine with strong CYP3A4/P-gp inhibitors in patients with renal or hepatic impairment - this can be fatal 1, 2, 3