Effect of low dose daily aspirin on serum urate levels and urinary excretion in patients receiving probenecid for gouty arthritis

Objective. To determine if low dose daily enteric coated aspirin significantly affects the therapeutic actions of probenecid with respect to serum urate levels or urinary urate excretion. Methods. Patients with gouty arthritis taking a stable dose of probenecid for at least 3 months were enrolled in a prospective crossover study. Twenty-four hour urinary and serum uric acid levels were measured after 14 days in patients crossed over to receive probenecid alone; probenecid and aspirin 325 mg taken concomitantly; and probenecid followed by aspirin 325 mg at 6 hours. Results. Eleven patients completed the crossover study. The addition of aspirin to a stable dose of probenecid had no significant effect upon serum urate levels or 24 h urinary urate excretion (p > 0.05, paired t test). Conclusion. Low dose daily enteric coated aspirin does not significantly interfere with the uricosuric effects of probenecid in patients with gouty arthritis.