Hi, Welcome to HCM! Yes, feboxostat does have some side effects. Serious side effects include cardiovascular events including myocardial infarction, liver enzyme abnormalities, weakness, numbness in extremities and shortness of breath. Uloric should not be used in patients treated with azathioprine or mercaptopurine. Call your doctor at once if you have a serious side effect such as: chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling; sudden numbness or weakness, especially on one side of the body; sudden headache, confusion, problems with vision, speech, or balance; or nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes). Less serious side effects may include: nausea; joint pain, swelling, or stiffness; mild skin rash; or dizziness. Hope that answers your query. Feel free to ask for any doubt. Wish you a speedy recovery. Regards, Dr. Sridhar Reddy