Why is Allopurinol not used for acute gout attacks?

Allopurinol Should Not Be Used for Acute Gout Attacks Because It Does Not Treat Acute Inflammation and May Prolong the Attack

Allopurinol is contraindicated during acute gout attacks because it does not address the underlying inflammation and may potentially prolong or worsen the acute attack. 1 Instead, anti-inflammatory medications should be used for acute gout management.

Mechanism of Action and Purpose

Allopurinol is a xanthine oxidase inhibitor that works by:

• Reducing uric acid production
• Gradually lowering serum urate levels over time
• Preventing future gout attacks through long-term urate reduction

This mechanism makes it inappropriate for acute attack management because:

1. It has no direct anti-inflammatory properties
2. It does not provide pain relief
3. It targets the underlying hyperuricemia rather than the acute inflammatory response

Evidence Against Using Allopurinol for Acute Attacks

The FDA drug label for allopurinol specifically notes that "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." 1

The 2017 American College of Physicians guideline states that "urate-lowering therapy does not reduce the risk for acute gout attacks in the first 6 months" and that "initiation of therapy to decrease serum urate levels is associated with an increased frequency of acute gout attacks." 2

Appropriate Management of Acute Gout

For acute gout attacks, the following medications should be used instead:

1. First-line options:

   • NSAIDs (if not contraindicated)
   • Colchicine (most effective when started within 12 hours of symptom onset)
   • Corticosteroids (oral or intra-articular)

2. Intra-articular approach:

   • Joint aspiration and injection of a long-acting steroid is effective for monoarticular attacks 2

When to Start Allopurinol

Allopurinol should be initiated:

• After the acute attack has resolved
• With appropriate anti-inflammatory prophylaxis
• Starting at a low dose (100 mg daily) and gradually titrating up 1

The European League Against Rheumatism (EULAR) recommends that "urate lowering therapy is indicated in patients with recurrent acute attacks, arthropathy, tophi, or radiographic changes of gout." 2

Prophylaxis When Starting Allopurinol

When initiating allopurinol therapy, prophylactic medication is essential:

• Colchicine (0.5-1 mg daily) or an NSAID should be given prophylactically 2
• Prophylaxis should be continued for at least 3-6 months after achieving target urate levels 3

A randomized controlled trial demonstrated that colchicine prophylaxis during allopurinol initiation significantly reduced the frequency of acute flares (0.52 vs. 2.91 flares, p=0.008) and their severity compared to placebo 4.

Recent Research Developments

Recent studies have challenged the traditional view about not starting allopurinol during acute attacks:

• A 2015 randomized clinical trial found no significant difference in days to resolution between starting allopurinol or placebo during an acute gout attack (15.4 vs. 13.4 days, p=0.5) 5
• A 2012 study showed no significant difference in daily pain scores when allopurinol was initiated during an acute attack 6
• A 2022 trial comparing early versus late allopurinol initiation found no significant difference in time to complete resolution of acute gout flare 7

However, these studies are small and relatively recent. The established clinical practice, supported by drug labeling and major guidelines, still recommends against initiating allopurinol during acute attacks without proper prophylaxis.

Common Pitfalls in Gout Management

1. Starting allopurinol without prophylactic anti-inflammatory medication
2. Discontinuing allopurinol during acute attacks (this should be avoided)
3. Inadequate patient education about potential flares when initiating therapy
4. Failure to titrate allopurinol dose to achieve target serum urate levels

Conclusion

While emerging research suggests that starting allopurinol during an acute attack may not significantly prolong it when appropriate anti-inflammatory medications are used concurrently, the established practice remains to treat the acute inflammation first with anti-inflammatory agents and initiate allopurinol after the acute attack has resolved, with appropriate prophylaxis.