Background/Purpose: Allopurinol is the most commonly used urate-lowering therapy (ULT) in the world. Although allopurinol is FDA approved for up to 800 mg/d and EMEA authorized for up to 900 mg/d, the majority of patients with gout receive ≤300 mg/d. We describe physician, patient, and treatment characteristics in patients with gout treated with allopurinol.

Methods: Data from a quantitative survey of physicians in the United States (US), France, Germany, Italy, Spain, and the United Kingdom (UK) were assessed and results confirmed through in-depth chart audits. Initial and current allopurinol doses, presence of comorbid conditions, use of anti-inflammatory prophylaxis for flare prevention, serum uric acid (sUA), physician subspecialty, and patient factors were evaluated. Data on number of patients achieving target sUA <6 mg/dL were also collected. Results are presented as proportions or means and standard deviations (SD). Descriptive statistics and multivariable-adjusted logistic regression analyses were used to describe patients with sUA <6 mg/dL.

Results: In total, 251 rheumatologists and 250 primary care physicians were interviewed. Of 2505 patients, 1437 (57%) were treated with allopurinol.

Table 1 presents patient characteristics, treatment, and percent with sUA <6 mg/dL.

Across all countries, the majority of patients were treated with ≤300 mg/d of allopurinol; ≤6.5% in France, Germany, and Spain were given >300 mg/d, whereas 10% in Italy, 19.6% in the US, and 34% in the UK achieved a dose >300 mg/d (p<0.01).  Over 12 months, the number of patients achieving target sUA <6.0 mg/dL differed across the 6 countries (Spain < Germany < Italy ≥600 mg/d of allopurinol. However, only physician subspecialty [general practitioners vs rheumatologists (OR 0.56; p<0.01)], UK vs other countries (OR 3.51; p<0.01), time on therapy (OR 1.39; p=0.04), and chart-documented coexisting alcoholism (OR 0.67; p<0.05), hyperlipidemia (OR 0.74; p<0.05), hypertension (OR 1.4; p<0.05), and kidney stones (OR 0.49; p<0.05) were found to be associated with achieving sUA <6 mg/dL. After adjusting for confounding factors (age, sex, time on ULT, dose, comorbid conditions, physician type), allopurinol dose was not associated with achieving sUA <6 mg/dL.

Conclusion: Allopurinol is the most widely used ULT. Although it is approved for up to 800 mg/d in the US and 900 mg/d in the EU, the majority of patients are treated with ≤300 mg/d. On average, <50% of patients achieve sUA <6 mg/dL at any allopurinol dose.