American Board of Internal Medicine (ABIM) Certification Practice Exam

How often should urate levels be rechecked in patients with CKD until allopurinol lowers serum urate below 6 mg/dL?

1. 1-2 weeks

2. 2-5 weeks

3. 4-6 weeks

4. 6-8 weeks

The correct answer is: 2-5 weeks

In the management of chronic kidney disease (CKD) with allopurinol therapy aimed at lowering urate levels, monitoring is crucial to ensure therapeutic effectiveness while minimizing potential side effects. The suggested interval for rechecking urate levels is 2-5 weeks. This timeframe strikes a balance between allowing sufficient time for the medication to take effect and allowing adjustments to therapy based on the patient's response. Allopurinol works to reduce uric acid production, making it important to monitor levels periodically to determine when they have reached the desired target of below 6 mg/dL. Rechecking too frequently, such as every 1-2 weeks, may not yield significant changes in urate levels, leading to unnecessary testing. Conversely, longer intervals beyond 5 weeks may delay the adjustment of therapy if urate levels remain elevated, which could increase the risk of complications from hyperuricemia. Thus, the 2-5 week interval is optimal for effective monitoring and management in this context.