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ASA (such as Anacin, Aspirin, or Bufferin) relieves pain and reduces fever and inflammation.

Warning: Do not give ASA to anyone younger than 20 unless your doctor tells you to do so because of the risk of Reye syndrome.

Be sure to follow the non-prescription medicine precautions.

Dosage: Adults (age 20 and older), 650 mg every 4 hours, as needed. Maximum adult dose is 4,000 mg in a 24-hour period.

ASA is a non-steroidal anti-inflammatory drug (NSAID). For information about other NSAIDs, see non-steroidal anti-inflammatory drugs (NSAIDs).

Side effects of ASA include:

  • Stomach upset or discomfort, which is the most common side effect. Taking ASA with food may help.
  • Ringing in the ears. Stop taking ASA or take a smaller dose until the ringing goes away.
  • Eye problems, such as blurred or double vision.
  • Dizziness.
  • Rapid, deep breathing.

Stop taking ASA and call a health professional if side effects do not go away within 4 hours after the last dose of ASA was taken.

Reasons not to take ASA

Do not take ASA if you:

  • Are allergic to ASA.
  • Are pregnant or trying to become pregnant.
  • Are breast-feeding.
  • Have asthma.
  • Have nasal polyps.
  • Have a blood-clotting disorder.
  • Have peptic ulcer disease.
  • Have a history of gastrointestinal bleeding.
  • Have a hangover.
  • Might have a low platelet count from chemotherapy or cancer.

Do not take ASA if you are taking:

  • Blood thinners (anticoagulants).
  • Oral diabetes medicines.


By Healthwise Staff
Primary Medical Reviewer William M. Green, MD - Emergency Medicine
Specialist Medical Reviewer H. Michael O'Connor, MD - Emergency Medicine
Last Revised October 5, 2009

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.