From the Guidelines
Allopurinol should not be initiated during an acute gout attack. Starting allopurinol during an acute flare can worsen and prolong the attack, as it can trigger crystal mobilization and worsen inflammation if started during an acute attack 1. Instead, the acute gout attack should first be treated with anti-inflammatory medications such as colchicine, NSAIDs (like naproxen or indomethacin), or corticosteroids.
Key Considerations
- Allopurinol can be started once the acute attack has resolved, typically 1-2 weeks after the inflammation subsides.
- When initiating allopurinol for long-term management, it should be started at a low dose (typically 100 mg daily) and gradually increased to reach the target uric acid level below 6 mg/dL.
- To prevent flares when starting allopurinol, prophylactic therapy with colchicine (0.6 mg once or twice daily) or a low-dose NSAID is recommended for 3-6 months.
- Allopurinol works by inhibiting xanthine oxidase, which reduces uric acid production.
Important Evidence
- High-quality evidence showed that prophylactic therapy with low-dose colchicine or low-dose NSAIDs reduces the risk for acute gout attacks in patients initiating urate-lowering therapy 1.
- Moderate-quality evidence also showed that continuing prophylactic treatment for more than 8 weeks was more effective than shorter durations to help prevent gout flares in patients initiating urate-lowering therapy 1.
- Febuxostat (40 mg/d) and allopurinol (300 mg/d) are equally effective at decreasing serum urate levels, but are associated with adverse effects, including rash with allopurinol and abdominal pain, diarrhea, and musculoskeletal pain with febuxostat 1.
From the FDA Drug Label
An increase in acute attacks of gout has been reported during the early stages of administration of allopurinol tablets, even when normal or subnormal serum uric acid levels have been attained. Past experience suggested that the most frequent event following the initiation of allopurinol treatment was an increase in acute attacks of gout (average 6% in early studies).
Allopurinol can exacerbate acute gout. It is not recommended to initiate allopurinol during an acute gout attack. Instead, prophylactic colchicine should be given when starting allopurinol to prevent acute gout attacks 2. The patient should start with a low dose of allopurinol (100 mg daily) and increase at weekly intervals by 100 mg until a serum uric acid level of 6 mg/dL or less is attained 2.
From the Research
Allopurinol Use in Acute Gout
- Allopurinol can be used during acute gout, as studies have shown that it does not prolong the acute, treated attack 3.
- The 2012 American College of Rheumatology Guidelines for the Management of Gout suggest that urate-lowering therapy, including allopurinol, can be started during an acute attack 3.
- Allopurinol is a first-line medication for the prevention of recurrent gout, and it can be initiated at a low dose during an acute gout attack in patients who meet criteria for starting urate-lowering therapy 4, 5.
Treatment of Acute Gout
- Acute gout is typically treated with nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, or colchicine 4, 6.
- Allopurinol is not typically used to treat acute gout attacks, but rather to prevent recurrent attacks by reducing uric acid levels 4, 5.
- Low-dose anti-inflammatory therapies can reduce gout flares during initiation of urate-lowering therapy, including allopurinol 5.
Important Considerations
- Patients with acute gout should be treated concurrently with nonsteroidal anti-inflammatory drugs, colchicine, or low-dose corticosteroids to prevent flares when starting urate-lowering therapy 4.
- Allopurinol should be started at a low dose, with gradual dose escalation, to minimize the risk of adverse effects 5.
- The use of allopurinol during acute gout should be individualized, taking into account the patient's medical history, comorbidities, and other medications 7.