Lack of effect of warfarin on uric acid concentration.

Uric acid concentrations reportedly are increased in patients being treated with warfarin. We measured uric acid in 40 patients before and during warfarin administration. The mean pre- and post-warfarin uric acid concentrations for our patients were 0.39 mmol/L and 0.40 mmol/L, respectively, not a significant difference. Further observations of hyperuricemic patients started on warfarin are needed to prove that their risk of gout is not increased.