Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).
Seek medical treatment if you have a serious drug reaction that can affect many parts of your body. Symptoms may include: skin rash, fever, swollen glands, flu-like symptoms, muscle aches, severe weakness, unusual bruising, or yellowing of your skin or eyes.
Call your doctor at once if you have:
a light-headed feeling, like you might pass out;
heart attack symptoms--chest pain or pressure, pain spreading to your jaw or shoulder, fast heartbeats, shortness of breath;
liver problems--stomach pain (upper right side), unusual tiredness, dark urine, jaundice (yellowing of the skin or eyes); or
signs of a stroke--sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with vision or balance.
Common side effects may include:
gout flares, joint pain;
nausea;
mild rash; or
liver problems.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Febuxostat side effects (more detail)
