Discontinue use if an allergic reaction occurs; if childn experience any sign of stomach bleeding (eg, feels faint, vomits blood, has bloody or black stools), have stomach pain that does not get better, redness or swelling present in the painful area, fever or pain gets worse or lasts >3 days, do not get any relief w/in 1st day of treatment, any new symptoms appear. May cause severe stomach bleeding. Severe or persistent sore throat or sore throat accompanied by high fever, headache, nausea & vomiting may be serious. May increase risk of heart attack or stroke if used more than or longer than directed.