Can allopurinol be used as needed for acute gout management?

From the Guidelines

Allopurinol should not be used as needed but rather taken daily as prescribed. This medication works by lowering uric acid levels in the body over time, which requires consistent daily dosing to be effective. Typical dosing starts at 100mg daily and may be increased gradually to 300-800mg daily based on uric acid levels and kidney function, as recommended by the 2016 updated EULAR evidence-based recommendations for the management of gout 1. Taking allopurinol intermittently or only during gout attacks is ineffective and can actually trigger flares. When starting allopurinol, it's essential to continue taking it even if you experience a gout attack, as these can occur initially when uric acid levels are changing. Most patients need to take allopurinol indefinitely to maintain normal uric acid levels and prevent gout attacks. The medication works by inhibiting xanthine oxidase, the enzyme responsible for producing uric acid, which is why consistent blood levels of the medication are necessary for it to work properly.

Some key points to consider:

• The American College of Physicians recommends against initiating long-term urate-lowering therapy in most patients after a first gout attack or in patients with infrequent attacks, as stated in the management of acute and recurrent gout: a clinical practice guideline from the American College of Physicians 1.
• Prophylactic therapy with low-dose colchicine or low-dose NSAIDs reduces the risk for acute gout attacks in patients initiating urate-lowering therapy, as shown by high-quality evidence 1.
• The most appropriate duration of urate-lowering therapy is insufficient, but moderate- to high-quality evidence suggests that urate-lowering therapy reduces the risk for acute gout attacks after 1 year, but not within the first 6 months of treatment 1.
• Febuxostat (40 mg/d) and allopurinol (300 mg/d) are equally effective at decreasing serum urate levels, but these drugs are associated with adverse effects, including rash with allopurinol and abdominal pain, diarrhea, and musculoskeletal pain with febuxostat 1.

Overall, the evidence suggests that allopurinol should be taken daily as prescribed to effectively manage gout and prevent future attacks, rather than using it as needed.

From the FDA Drug Label

Allopurinol tablets are indicated in: 1. the management of patients with signs and symptoms of primary or secondary gout (acute attacks, tophi, joint destruction, uric acid lithiasis, and/or nephropathy). Treatment with allopurinol tablets should be discontinued when the potential for overproduction of uric acid is no longer present. 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.

The FDA drug label does not answer the question of using allopurinol as needed. The label provides information on the indications, dosage, and administration of allopurinol, as well as potential adverse reactions, but it does not specifically address the use of allopurinol on an as-needed basis 2, 2, 2.

From the Research

Allopurinol Usage

• Allopurinol is a commonly used medication for the treatment of gout, a form of inflammatory arthritis 3, 4, 5, 6.
• The medication is typically used to lower uric acid levels in the blood, which can help prevent gout flares 4, 5, 6.
• The standard dosage of allopurinol is usually started at 100 mg per day and can be titrated up to 800 mg per day, depending on the patient's response and serum urate levels 5.

As-Needed Usage

• There is no clear evidence to support the use of allopurinol on an as-needed basis 3, 4, 5, 7, 6.
• Allopurinol is typically used as a long-term treatment to prevent gout flares, rather than as a treatment for acute flares 4, 5, 6.
• The medication is usually taken daily, rather than on an as-needed basis, to maintain consistent uric acid levels and prevent gout flares 3, 4, 5.

Important Considerations

• Patients with certain comorbidities, such as chronic kidney disease, may require adjusted dosing or closer monitoring while taking allopurinol 4, 5, 6.
• Allopurinol can cause severe adverse hypersensitivity reactions, sometimes even fatal, and patients should be closely monitored for signs of these reactions 7, 6.
• The use of allopurinol in asymptomatic patients with hyperuricemia is not recommended, as the potential benefits do not outweigh the potential risks 7.