What Is Allopurinol Failure and What Should We Do About It?

Allopurinol is the most widely used urate-lowering medication worldwide. However, allopurinol failure is frequently observed in clinical practice. In this review, we provide a framework for assessing allopurinol failure, which includes failure of allopurinol to control serum urate concentrations, failure of allopurinol to control clinical symptoms, and failure of allopurinol due to an adverse drug reaction. Understanding the causes of allopurinol failure underpins the approach required to turn failure into success in gout management.