Febuxostat is a xanthine oxidase inhibitor used primarily for the long-term treatment of hyperuricemia with symptoms of gout; it is not recommended for patients with asymptomatic hyperuricemia. It is administered at a starting dose of 40 mg/day without dose adjustment in patients with mild to moderate renal insufficiency, mild to moderate hepatic impairment, or in the elderly. The course of the drug is to be applied for at least 6 months. A non-steroidal anti-inflammatory analgesic or colchicine should be given along with the drug to prevent acute attacks of gout. Common adverse effects of this drug include abnormal liver function, nausea and arthralgia and are contraindicated in patients currently taking azathioprine, mercaptopurine and cholecalciferol.