Reye's syndrome: Children and teenagers who have or are recovering from chicken pox or flu-like symptoms should not use this product. When using this product, if changes in behavior with nausea and vomiting occur, consult a doctor because these symptoms could be an early sign of reye's syndrome, a rare but serious illness. Allergy alert aspirin may cause severe allergic reaction which may include: hives, facial swelling, shock, asthma (wheezing).. Stomach bleeding warning: this product contains an NSAID, which may cause severe stomach bleeding. The chance is higher if you are age 60 or older, have had stomach ulcers or bleeding problems, take a blood thinning (anticoagulant) or steroid drug, take other drugs containing prescription or non-prescription NSAIDs (aspirin, ibuprofen, naproxen, or others), have 3 or more alcoholic drinks every day while using this product, take more or for a longer time than directed. Caffeine warning: The recommended dose of this product contains about as much caffeine as a cup of coffee. Limit the use of caffeine-containing medications, foods, or beverages while taking this product because too much caffeine may cause nervousness, irritability, sleeplessness, and, occasionally, rapid heart beat. Do not use for more than 2 days for a hangover unless directed by a doctor. Not intended for use as a substitute for sleep. If fatigue or drowsiness persists or continues to recur, consult a doctor, if you have ever had an allergic reaction to aspirin or any other pain reliever/fever reducer, in children under 12 years of age.. Ask a doctor before use if stomach bleeding warning applies to you, you have a history of stomach problems, such as heartburn, you have high blood pressure, heart disease, liver cirrhosis, or kidney disease, you are taking a diuretic, you have asthma.. Ask a doctor or pharmacist before use if you are taking a prescription drug for diabetes, gout, arthritis.. Stop use and ask a doctor if an allergic reaction occurs. Seek medical help right away., you experience any of the following signs of stomach bleeding:, feel faint, vomit blood, have bloody or black stool, have stomach pain that does not get better, any new symptoms appear, ringing in the ears or a loss of hearing occurs. these could be signs of a serious condition.. If pregnant or breast-feeding, ask a health professional before use. It is especially important not to use aspirin during the last 3 months of pregnancy unless definitely directed to do so by a doctor because it may cause problems in the unborn child or complications during delivery. Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center (1-800-222-1222) right away. Tamper Evident: Do not use if pack is damaged or open.