 The febuxostat drug labels already carry a warning and precaution about cardiovascular events because the clinical trials conducted before approval showed a higher rate of heart-related problems in patients treated with febuxostat compared to allopurinol.These problems included heart attacks, strokes, and heart-related deaths.As a result, the FDA required an additional safety clinical trial after the drug was approved and on the market to better understand these differences, and that trial was finished recently.