Six months ago, I prescribed allopurinol(Drug information on allopurinol) for a patient with a history of podagra, several tophi in one toe, and an elevated uric acid level. The level has dropped to the low end of the normal range, and his urinary uric acid excretion is quite low. Yet despite treatment, he has had 2 more episodes of gout. Do you have any suggestions?
The first step is to confirm that your patient's "tophus" is not a subcutaneous nodule such as those associated with rheumatoid arthritis. This can be done by aspirating the nodule; the presence of monosodium urate crystals in the aspirate confirms tophaceous gout.
Optimal treatment requires a long-standing reduction in serum urate levels. It has been proposed that maintaining a serum urate level of less than 6 mg/dL—rather than a level in the normal range—will help ensure resolution of tophi and eventual cessation of acute gouty attacks.
Increase your patient's allopurinol dosage sufficiently to lower the serum urate level to less than 6 mg/dL and then measure the tophi to confirm that their size has decreased. The maximum effect from lowering serum urate levels occurs within 14 days. Thus, check levels 3 to 6 weeks after changing the allopurinol dosage. Continue to increase the dosage until the serum urate level falls below 6 mg/dL.
A potential problem with this approach is that a major change in the serum urate level induced by initiating a urate-lowering drug (such as allopurinol) or changing the dosage may precipitate a gouty attack or prolong an attack already in progress. Colchicine(Drug information on colchicine) is commonly used as prophylaxis against gouty attacks. Colchicine, 0.5 to 0.6 mg bid until the serum urate level drops below 6 mg/dL, significantly reduces the frequency of attacks of acute gout in patients whose hyperuricemia is controlled by allopurinol.
— Naomi Schlesinger, MD
Associate Professor of Medicine
Director, Clinical Rheumatology
University of Medicine and Dentistry of New Jersey/
Robert Wood Johnson Medical School