Trends in Utilization of Urate-Lowering Therapies Following the US Food and Drug Administration's Boxed Warning on Febuxostat.

Gout is the most common inflammatory arthritis affecting nearly 4% of adults (9.2 millions) in the U.S. Initiation of urate-lowering therapy (ULT) is strongly recommended for all patients with tophaceous gout, radiographic damage, or frequent gout flares. While allopurinol is the first-line ULT, some patients do not tolerate or adequately respond to allopurinol and require a different ULT such as febuxostat. At the time of approval of febuxostat in February 2009, the U.S. Food and Drug Administration (FDA) mandated a post-marketing cardiovascular safety trial (the CARES trial) to address concerns related to cardiovascular risk raised during premarketing trials.