Gout is a chronic urate crystal deposition disorder, which if left untreated may result in progressive disease characterized by joint and bone destruction from tophaceous deposits and renal impairment due to gouty nephropathy. Hyperuricemia, defined as a serum urate concentration of >7.0 milligrams per deciliter (mg/dL), is the underlying metabolic aberration leading to urate crystal deposition in gout. Gout has several clinical presentations, including: recurrent acute attacks of inflammatory arthritis; deposition of monosodium urate monohydrate crystals in joints, bones and even parenchymal organs (tophaceous gout); renal impairment; and uric acid nephrolithiasis. As serum urate levels increase beyond >7.0 mg/dL, the risks for gouty arthritis or for renal calculi increase.
Currently allopurinol is the only xanthine oxidase inhibitor available. Allopurinol is the agent of choice for reduction of serum urate levels in patients with: uric acid overproduction; unresponsive or intolerant to uricosuric agents; impaired renal function; uric acid urolithiasis; or tophi.
Febuxostat (TMX-67) is a non-purine selective xanthine oxidase inhibitor being developed as an orally administered agent for management of hyperuricemia in patients with gout.
Read more: http://www.clinicaltrials.gov/ct2/show/NCT00174967?cond=%22Arthritis%22&lup_s=07/14/2011&lup_d=30