[Gout: an overview of available urate lowering therapies]

The aim of urate-lowering therapy is to maintain urate concentration below the saturation point for monosodium urate. This therapy dissolves crystal deposits and cures gout while it is maintained. EULAR guidelines recommend that plasma urate should be maintained at a concentration less than 360μM, and the British Guidelines less than 300μM. Urate-lowering therapy is indicated for patients with recurrent gout attacks, chronic arthropathy, tophi, and gout with uric acid stones. Allopurinol lowers uricemia through inhibition of xanthine oxidase activity. The maximum allowed dose is reduced in case of renal failure, which is relatively frequent in gouty patients. Febuxostat has been approved for the treatment of chronic hyperuricemia in conditions where urate deposition has already occurred. Febuxostat is a novel non-purine, selective inhibitor of xanthine oxidase, metabolized and excreted by the liver, so no dose adjustment appears to be necessary in patients with mild-to-moderate renal impairment. Another powerful hypo-uricemic drug is the PEG-uricase (pegloticase). Pegloticase is a uric acid-specific PEGylated recombinant mammalian uricase recently approved by the FDA for treatment of patients with refractory chronic gout.