 The adverse effects associated with febuxostat therapy include nausea, diarrhea, arthralgia, headache, increased hepatic serum enzyme levels and rash.On 15 November 2017, the FDA issued a safety alert indicating that the preliminary results from a safety clinical trial showed an increased risk of heart-related death with febuxostat compared to allopurinol.The FDA required Takeda to conduct this safety study when the medicine was approved in 2009.