Immediately stop treatment if serious allergic/hypersensitivity reactions, including SJS, occur. Avoid treatment in patients w/ pre-existing major CV disease (eg, MI, stroke or unstable angina). Cardiac monitoring in patients undergoing chemotherapy for haematologic malignancies at intermediate to high risk of TLS. Do not start treatment until an acute gout attack has completely subsided. Gout flares may occur during treatment initiation; flare prophylaxis for at least 6 mth w/ NSAID or colchicine is recommended. Perform liver function test prior to treatment initiation & periodically thereafter based on clinical judgment. Use w/ caution in patients w/ altered thyroid function. Not recommended in patients w/ Lesch-Nyhan syndrome; patients concomitantly treated w/ mercaptopurine/azathioprine; organ transplant recipients. Should not be taken by patients w/ rare hereditary problems of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption. May impair ability to drive or operate machinery. Patients w/ severe renal impairment (CrCl <30 mL/min); severe hepatic impairment (Child-Pugh class C); moderate hepatic impairment in gout. Do not use during pregnancy & breastfeeding. Childn <18 yr.