From the Guidelines
Allopurinol should not be initiated during an acute gout attack because it can worsen or prolong the attack, and instead, acute gout should first be managed with anti-inflammatory medications such as colchicine, NSAIDs, or corticosteroids, as recommended by the 2020 American College of Rheumatology guideline for the management of gout 1.
Reasons for Not Initiating Allopurinol During Acute Gout
- Starting allopurinol during an acute flare can trigger the release of urate crystals from tissue deposits as serum uric acid levels begin to decrease, which can exacerbate inflammation and pain.
- The 2016 updated EULAR evidence-based recommendations for the management of gout suggest that acute flares of gout should be treated as early as possible with anti-inflammatory medications, and urate-lowering therapy (ULT) should be considered and discussed with every patient with a definite diagnosis of gout from the first presentation 1.
- The 2020 American College of Rheumatology guideline for the management of gout conditionally recommends starting ULT during the gout flare, but this should be done with caution and under the guidance of a healthcare professional 1.
Management of Acute Gout
- Acute gout should be managed with anti-inflammatory medications such as:
- Colchicine
- NSAIDs like naproxen or indomethacin
- Corticosteroids
- These medications can help reduce inflammation and pain associated with acute gout attacks.
- The choice of medication should be based on the presence of contraindications, the patient’s previous experience with treatments, time of initiation after flare onset, and the number and type of joint(s) involved 1.
Initiation of Allopurinol
- Allopurinol therapy should be initiated only after the acute attack has completely resolved, typically 1-2 weeks after inflammation subsides.
- When starting allopurinol, it should be introduced at a low dose (typically 100mg daily) and gradually increased to reach target uric acid levels below 6 mg/dL.
- To prevent flares during allopurinol initiation, prophylactic therapy with low-dose colchicine (0.6mg once or twice daily) or a low-dose NSAID is recommended for 3-6 months 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 is not prescribed in acute gout because it can worsen the condition by increasing the frequency of acute attacks, at least in the early stages of treatment 2, 2.
- The exact mechanism is not fully understood, but it may be related to the mobilization of urates from tissue deposits, causing fluctuations in serum uric acid levels.
- It is recommended to start with a low dose of allopurinol and gradually increase it to minimize the risk of acute attacks 2.
From the Research
Reasons for Not Prescribing Allopurinol in Acute Gout
- Allopurinol is used to reduce concentrations of uric acid, but it is not typically used to treat acute gout attacks 3.
- The standard pharmacotherapies for gout flares include colchicine, NSAIDs, and oral or intramuscular corticosteroids, with IL-1 inhibitors as an option for flare refractory to standard therapies 4.
- Acute gout is traditionally treated with NSAIDs, corticosteroids, and colchicine, and there is no mention of allopurinol as a treatment option for acute gout in several studies 5, 6, 7.
- Prophylaxis of acute gout with NSAIDs, colchicine, or corticosteroids is recommended when initiating any urate-lowering therapy, such as allopurinol, to prevent acute gouty arthritis for a period of at least 6 months 7.
- Allopurinol is an effective treatment for reducing concentrations of uric acid, but it is not used to treat acute gout attacks, instead, it is used to prevent gout flares as part of urate-lowering therapy 3, 4.