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Aspirin Patient Tips

How it works

Aspirin blocks the effects of an enzyme, cyclooxygenase which in turn prevents the synthesis of prostaglandin. This gives it its pain-relieving and anti-inflammatory properties. It also has an effect on the way platelets stick together which helps it to prevent blood clots from forming in the heart. It is a type of nonsteroidal anti-inflammatory drug (NSAID).


  • Used to treat headache, pain, and relieve fever.
  • Can be used short-term to relieve symptoms of colds, muscle trauma, menstruation, toothache, and arthritis .
  • Used in small doses following various heart-related procedures to ensure blood flows freely around the body.
  • Used to reduce the risk of death or stroke in people with a history of stroke due to blood clots or previous stroke-like events.
  • Used to help prevent another heart attack or reduce the risk of death in people at risk of a heart attack, or who already have angina.
  • Also used off-label for several other conditions (e.g. polycythemia vera). Off-label means it is not FDA approved for this use, but there may be data to show it is safe and effective.


If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Stomach pain/irritation, heartburn, nausea and tinnitus (ringing in the ears); risk increased with higher dosages.
  • Stomach bleeding and a prolonged bleeding time (risk is higher in people who smoke, who drink more than 3 glasses of alcohol per day or take other medicines that affect bleeding time).

Notes: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. For a complete list of all side effects, click here.

Bottom Line

Aspirin relieves pain and inflammation and helps thin the blood and is used for multiple conditions. Can cause stomach irritation and increase bleeding risk


  • For suspected heart attack, chew a non-coated 325 mg tablet of aspirin as soon as possible and call 911.
  • Unless you suspect you are having a heart attack, always seek your doctor's advice before taking aspirin.
  • Take aspirin with food or after meals.
  • Administer each dose of aspirin with a full glass of water, unless you have been told to restrict fluids.
  • Do not crush or chew delayed- or slow-release preparations .
  • Aspirin comes in various strengths. Make sure you are taking the right amount for your condition and your age.
  • Do not use in children or teenagers with flu symptoms, fever, or chicken pox due to the possibility of Reye's syndrome (rare but serious condition that causes swelling in the brain and liver).
  • For most heart conditions, the typical maintenance dose is 81 mg once daily.
  • Dosages given for pain relief are generally higher than those given for heart conditions .
  • Small amounts of antacids taken with aspirin may decrease stomach irritation.
  • Avoid buffered aspirin products if you are on a sodium-restricted diet.
  • Seek emergency help if you experience any head or neck swelling, difficulty breathing or severe itching after taking aspirin.
  • Tell your doctor if you experience ringing in your ears, persistent stomach pain, persistent indigestion or blackened stools while taking aspirin.
  • Treatment with aspirin may need to be stopped a couple of weeks before surgery; check with your doctor.
  • Do not use for at least 7 days after tonsillectomy or oral surgery unless directed by your doctor.

Response and Effectiveness

  • Takes from 5 to 30 minutes (depending on formulation) for aspirin to have an effect on platelet function. Chewed non-coated formulations work faster.
  • Needs to be taken daily to inhibit new platelets that are constantly being released into the circulation; however, platelet inhibition lasts the platelet lifetime (~10 days) due to permanent inhibition of platelet COX-1 enzyme.


Aspirin [package insert]. Revised 02/2010. HIMPRIT PHARMACHEM PVT LTD. Accessed 02/2016 Aspirin for heart attack. Chew or swallow? Revised 10/2015. Harvard Health Publications. Harvard Medical School. Accessed 02/2016 Paikin J, Eikelboom J. Aspirin. Cardiology Patient Page. Circulation. 2012; 125: e439-e442 Accessed 02/2016

  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use aspirin only for the indication prescribed.

  • Disclaimer: Every effort has been made to ensure that this information is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This drug information does not endorse drugs, diagnose patients or recommend therapy. It is an informational resource designed as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of this information. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2017 Revision Date: 2015-12-16 23:05:18