- A Visual Guide to Migraine Headaches Slideshow
- Headache and Migraine Triggers Slideshow
- Take the Migraines Quiz
- What is aspirin? How does it work (mechanism of action)?
- What are the uses for aspirin?
- What are the side effects of aspirin?
- What is the dosage for aspirin?
- Which drugs or supplements interact with aspirin?
- Is aspirin safe to take if I'm pregnant or breastfeeding?
- What else should I know about aspirin?
What is aspirin? How does it work (mechanism of action)?
Aspirin is a nonsteroidal antiinflammatory drug (NSAID) effective in treating fever, pain, and inflammation in the body. It also prevents blood clots (i.e., is antithrombotic). As a group, NSAIDs are non-narcotic relievers of mild to moderate pain of many causes, including
Other members of this class include ibuprofen (Motrin), indomethacin (Indocin), nabumetone (Relafen) and several others. They all work by reducing the levels of prostaglandins, chemicals that are released when there is inflammation and that cause pain and fever. NSAIDs block the enzyme that makes prostaglandins (cyclooxygenase), resulting in lower concentrations of prostaglandins. As a consequence, inflammation, pain, and fever are reduced. Inhibition of prostaglandins also reduces the function of platelets and the ability of blood to clot. Aspirin, inhibits the function of platelets in a manner that is different from other NSAIDs, and its antithrombotic effects last longer than other NSAIDs. This is why aspirin is used for preventing heart attacks and strokes. The FDA approved Bayer aspirin in June 1965.
What are the uses for aspirin?
Aspirin is used for the treatment of inflammation, fever, and pain that results from many forms of arthritis, including:
- Rheumatoid arthritis
- Juvenile rheumatoid arthritis
- Systemic lupus erythematosus
- Ankylosing spondylitis
- Reiter's syndrome
- Soft tissue injuries, such as tendinitis and bursitis
Aspirin also is used for rapid relief of mild to moderate pain and fever in other inflammatory conditions. Because aspirin inhibits the function of platelets for prolonged periods of time, it is used for reducing the risk of another stroke or heart attack in people who have already had a stroke or heart attack.
What are the side effects of aspirin?
Most patients benefit from aspirin and other NSAIDs with few side effects. However, serious side effects can occur and generally tend to be dose-related. Therefore, it is advisable to use the lowest effective dose to minimize side effects.
The most common side effects of aspirin involve the gastrointestinal system and ringing in the ears.
Gastrointestinal side effects are
- abdominal burning,
- gastritis, and
- even serious gastrointestinal bleeding and
- liver toxicity.
Ringing in the ears
- Should ringing in the ears occur, the daily dose should be reduced.
Other side effects include:
Other side effects and adverse reactions
- Aspirin should be avoided by patients with peptic ulcer disease or poor kidney function, since this medication can aggravate both conditions.
- Aspirin may exacerbate asthma.
- Aspirin can raise the blood uric acid level and is avoided in patients with hyperuricemia and gout.
- Children and teenagers should avoid aspirin for symptoms of the flu or chickenpox because of the associated risk of Reye's Syndrome, a serious disease of the liver and nervous system that can lead to coma and death.
- Aspirin can increase the effect of medicines used to treat diabetes mellitus, resulting in abnormally low blood sugars if blood sugar levels are not monitored.
- NSAIDs should be discontinued prior to elective surgery because of a mild tendency to interfere with blood clotting. Aspirin, because of its prolonged effect on platelets, is best discontinued at least ten to fourteen days in advance of the procedure.
What is the dosage for aspirin?
Aspirin should be taken with food. Doses range from 50 mg to 6000 mg daily depending on the use.
- Usual doses for mild to moderate pain are 350 or 650 mg every 4 hours or 500 mg every 6 hours.
- Doses for rheumatoid arthritis include 500 mg every 4-6 hours; 650 mg every 4 hours; 1000 mg every 4-6 hours; 1950 mg twice daily.
- Heart attacks are prevented with 75, 81, 162 or 325 mg daily.
- 160 to 325 mg of non-enteric coated aspirin should be chewed immediately when experiencing symptoms of a heart attack.
- The dose for preventing another stroke is 75 to 100 mg daily.
Which drugs or supplements interact with aspirin?
Aspirin is associated with several suspected or probable interactions that affect the action of other drugs. The following examples are the most common of the suspected interactions.
Aspirin may reduce the blood pressure lowering effects of blood pressure medications. This may occur because prostaglandins have a role in the regulation of blood pressure.
When aspirin is used in combination with methotrexate (Rheumatrex, Trexall) or aminoglycoside antibiotics (for example, gentamicin) the blood levels of the methotrexate or aminoglycoside may increase, presumably because their elimination from the body is reduced. This may lead to more methotrexate or aminoglycoside-related side effects.
Individuals taking oral blood thinners or anticoagulants, for example, warfarin, (Coumadin) should avoid aspirin because aspirin also thins the blood, and excessive blood thinning may lead to serious bleeding.
Migraines and Headaches Resources
Is aspirin safe to take if I'm pregnant or breastfeeding?
Aspirin is excreted into breast milk and may cause adverse effects in the infant.
What else should I know about aspirin?
What preparations of acetylsalicylic acid are available?
Chewable tablets: 81mg; caplets and tablets: 325mg, 500mg; enteric coated (safety coated) caplets and tablets: 325mg, 500mg.
How should I keep acetylsalicylic acid stored?
Aspirin should be stored at room temperature, 20 C to 25 C (68 F to 77 F), in a sealed container, avoiding moisture.
Aspirin is available is available in generic form without a prescription from your doctor or other healthcare professional.
Aspirin (Aspirin, Arthritis Foundation Safety Coated Aspirin, Bayer Aspirin, Bayer Children's Aspirin, Ecotrin, and many others) is a NSAID used to treat fever, pain, and inflammation in the body that results from forms of arthritis, and soft tissue injuries. Aspirin is also used for decreasing the risk of heart attacks and strokes. Side effects, drug interactions, pregnancy information, and pregnancy safety information should be reviewed prior to taking any medication.
Multimedia: Slideshows, Images & Quizzes
Rheumatoid Arthritis Quiz: What is Rheumatoid Arthritis?
How is rheumatoid arthritis different from other forms of arthritis, such as osteoarthritis and gout? Take the Rheumatoid...
Heart Disease Quiz: Test Your Medical IQ
Take our Heart Disease Quiz to get answers and facts about high cholesterol, atherosclerosis prevention, and the causes,...
Picture of Fixed Drug Eruption
A large red-violet plaque on the arm of a child. See a picture of Fixed Drug Eruption and learn more about the health topic....
Abdominal Pain: Common Causes of Stomach Pain in Children
Abdominal pain in children can be more than just a tummy ache. What are the common causes of abdominal pain in children? Learn...
Tinnitus: Why Are My Ears Ringing?
What is tinnitus? Explore tinnitus (ringing in the ears) causes, symptoms, relief remedies, treatments and prevention tips. Learn...
Food Swaps for Meals and Snacks for Heart Health in Pictures
Explore 10 food swaps for heart-wise dining. Learn what food to buy and how to cook in order to make a big difference for your...
Related Disease Conditions
Sore Throat Home Remedies (Soothe, Pain Relief)
Natural and home remedies for sore throat symptoms and pain relief include essential oils, licorice gargles, slippery elm...
Bursitis of the hip results when the fluid-filled sac (bursa) near the hip becomes inflamed due to localized soft tissue trauma...
Shoulder and Neck Pain
Shoulder and neck pain may be caused by bursitis, a pinched nerve, whiplash, tendinitis, a herniated disc, or a rotator cuff...
A dry socket is a potential complication that can occur when a blood clot in the gums becomes dislodged after a tooth extraction....
Gastritis Symptoms, Causes, Diet, Home Remedies, Treatment, and Cure
Gastritis (acute and chronic) is an inflammation of the lining of the stomach Some people have no gastritis symptoms, but when...
Stroke (Signs, Symptoms, Warning Signs)
A stroke is an interruption of the blood supply to part of the brain caused by either a blood clot (ischemic) or bleeding...
Headaches can be divided into two categories: primary headaches and secondary headaches. Migraine headaches, tension headaches,...
Coccydynia (Tailbone Pain)
Coccydynia is an inflammation of the bony area (tailbone or coccyx) located between the buttocks. Coccydynia is associated with...
Lower Back Pain
There are many causes of back pain. Pain in the low back can relate to the bony lumbar spine, discs between the vertebrae,...
Sciatica pain, caused by irritation of the sciatic nerve, typically radiates from the low back to behind the thigh to below the...
Chronic Rhinitis and Post-Nasal Drip (Symptoms, Treatment)
Chronic rhinitis and post-nasal drip symptoms include an itchy, runny nose, sneezing, itchy ears, eyes, and throat. Seasonal...
Sore throat (throat pain) usually is described as pain or discomfort in the throat area. A sore throat may be caused...
Polycythemia (High Red Blood Cell Count)
Polycythemia (elevated red blood cell count) is a rare blood disease in which the body produces too many red blood cells....
Neck Pain (Cervical Pain)
Neck pain (cervical pain) may be caused by any number of disorders and diseases. Tenderness is another symptom of neck pain....
Rheumatoid arthritis (RA) is an autoimmune disease that causes chronic inflammation of the joints, the tissue around the joints,...
Raynaud's phenomenon is characterized by a pale-blue-red sequence of color changes of the digits, most commonly after exposure to...
Peripheral Neuropathy (Causes, Symptoms, Treatment Medications)
Peripheral neuropathy is a problem with the functioning of the nerves outside of the spinal cord. Symptoms may include numbness,...
Migraine headache is a type of headache associated with a sensitivity to light, smells, or sounds, eye pain, severe pounding on...
Arthritis is inflammation of one or more joints. When joints are inflamed they can develop stiffness, warmth, swelling, redness...
Acute injuries, medical conditions, and chronic use conditions are causes of knee pain. Symptoms and signs that accompany knee...
Tension Headache (Symptoms, Relief, Causes, Treatment)
A tension headache s one of the most common types of headaches, and the exact cause is not known. Factors that may contribute to...
Night Sweats (In Men and Women) Causes, Remedies, and Treatments
Night sweats are severe hot flashes that occur at night and result in a drenching sweat. The causes of night sweats in most...
Pericarditis (Symptoms, ECG, Types, Causes, Treatment)
Pericarditis is the inflammation of the pericardial sac that surrounds the heart. The causes of pericarditis include injury from...
A heart attack happens when a blood clot completely obstructs a coronary artery supplying blood to the heart muscle. A heart...
Shoulder bursitis is inflammation of the shoulder bursa. Bursitis may be caused by injury, infection, or a rheumatic condition....
Moles are small skin growths that may appear flat or raised and are often tan, brown, black, reddish brown, or skin colored. They...
A bursa is a fluid-filled sac found in the joints that cushions them. Bursitis is an inflammation of the bursae, most commonly...
Osteoarthritis is a type of arthritis caused by inflammation, breakdown, and eventual loss of cartilage in the joints. Also...
Intermittent claudication, or pain and cramping in the lower leg is caused by inadequate blood flow to the leg muscles. This lack...
Lupus (Systemic Lupus Erythematosus or SLE)
Systemic lupus erythematosus is a condition characterized by chronic inflammation of body tissues caused by autoimmune disease....
Ankle pain is commonly due to a sprain or tendinitis. The severity of ankle sprains ranges from mild (which can resolve within...
Mastoiditis (Symptoms, Treatment, Cure in Adults and Children
Mastoiditis in children and adults is inflammation and/or infection of the mastoid bone, which is located behind the ear. The...
A Baker's cyst, also called a popliteal cyst, is swelling caused by knee joint fluid protruding to the back of the knee...
Angina (Symptoms, Causes, Types, Diagnosis, and Treatment)
Angina is chest pain due to inadequate blood supply to the heart. Angina symptoms may include chest tightness, burning,...
The common bunion, an enlargement of the inner portion of the joint at the base of the big toe, primarily affects women. The...
Hamstring injuries may range from minor strains to major ruptures. A hamstring injury causes spasm, tightness, and tenderness....
Chest pain is a common complaint by a patient in the ER. Causes of chest pain include broken or bruised ribs, pleurisy,...
Polymyalgia rheumatica (PMR) is a disorder of the muscles and joints that causes pain and stiffness in the arms, neck, shoulders,...
Costochondritis and Tietze Syndrome
Costochondritis is inflammation of the cartilage where the ribs attach to the sternum. Tietze syndrome affects the same region of...
Dengue fever is contracted from the bite of a striped Aedes aegypti mosquito. Symptoms and signs of dengue include headache,...
Pain that originates in the face is referred to as trigeminal neuralgia. This pain may be caused by: an injury, an infection...
Fabry Disease (Symptoms and Life Expectancy)
Fabry disease (Fabry's disease, alpha-galactosidase-A) is a genetic disorder with symptoms such as burning sensations in...
Chronic pain is pain (an unpleasant sense of discomfort) that persists or progresses over a long period of time. In contrast to...
Carpal Tunnel Syndrome
Carpal tunnel syndrome is a condition in which irritation of the wrist's median nerve causes tingling and numbness of the thumb,...
Whiplash is a common injury to a person's neck following a car accident (in most cases). Symptoms include: headache, neck...
Spider Bites (Black Widow and Brown Recluse)
Most spiders in the United States are harmless; however, black widow and brown recluse spider bites may need medical treatment....
Elbow pain is most often the result of tendinitis, which can affect the inner or outer elbow. Treatment includes ice, rest, and...
Labyrinthitis (Inner Ear Inflammation) Symptoms, Causes, Contagious, Treatment Cure
Labyrinthitis is inflammation of the labyrinth (the part of the ear responsible for balance and hearing). Doctors do not know...
Still's disease (systemic-onset juvenile rheumatoid arthritis) is a disorder characterized by inflammation with high fever...
Psoriatic arthritis is a disease that causes skin and joint inflammation. Symptoms include painful, stiff, and swollen joints,...
Prostatitis vs. BPH (Enlarged Prostate) Differences and Similarities
Prostatitis and BPH (benign prostatic hyperplasia, enlarged prostate gland) are both conditions of the prostate gland. There...
A Morton's neuroma is an inflamed nerve between the bones at the ball of the foot. Symptoms include a burning, sharp pain on the...
Migraines and Seizures (Symptoms, Auras, Medication)
Migraines are a type of headache and seizures are the main symptom of epilepsy. Migraine headaches and seizures are two...
Antiphospholipid syndrome (phospholipid antibody syndrome or Hughes syndrome) is an immune system disorder with symptoms that...
Interstitial Cystitis (IC) and Painful Bladder Syndrome (PBS)
Interstitial cystitis (IC)/painful bladder syndrome (PBS) is an inflammatory disease of the bladder that can cause ulceration and...
A frozen shoulder (adhesive capsulitis) is when the shoulder joint experiences a significant loss in its range of motion due to...
Rotator Cuff Disease
Rotator cuff disease is damage to any of the four tendons that stabilize the shoulder joint. Shoulder pain and tenderness are...
Nonsteroidal Anti-inflammatory Drugs and Ulcers
Nonsteroidal antiinflammatory drugs (NSAIDs) are prescribed medications for the treatment of inflammatory conditions. Examples of...
SAPHO syndrome is a chronic disorder that involves the skin, bone, and joints. SAPHO syndrome is an eponym for the combination of...
Reye's syndrome (RS or Reye syndrome) is a sudden, sometimes fatal, disease of the brain with degeneration of the liver. Reye...
Atrial Fibrillation (AFib) Treatment Drugs
Atrial fibrillation (also called Afib or Afib) is heart rhythm disorder that causes irregular, and often, a rapid heartbeat. The...
Eosinophilic Fasciitis (Shulman's Syndrome)
Eosinophilic fasciitis is a skin disease that causes thickening and inflammation of the skin and fascia. Symptoms include...
Kawasaki disease is a rare children's disease characterized by a fever that lasts more than five days and at least four of the...
Heart Attack Treatment
A heart attack involves damage or death of part of the heart muscle due to a blood clot. The aim of heart attack treatment is to...
Juvenile Idiopathic Arthritis (Juvenile Rheumatoid Arthritis)
Juvenile idiopathic arthritis (juvenile rheumatoid arthritis or JRA) annually affects one child in every thousand. There are six...
Menstrual Cramps and Premenstrual Syndrome (PMS) Medication Guide
Menstrual cramps and premenstrual syndrome (PMS) symptoms include abdominal cramping, bloating, a feeling of fullness, abdominal...
Laryngitis Home Remedies (in Adults and Children)
Laryngitis is an inflammation of the larynx. Inflammation of the larynx is most often caused by viral infections, and have...
Stroke is the third leading killer in the United States. Some of the warning signs of stroke include sudden confusion, trouble...
Migraine and Stroke (Symptoms, Types, Causes, Treatment)
Migraine headache is a type of headache in which the exact cause is not known; however, they may be inherited, and certain...
Giant Cell Arteritis (GCA or Temporal Arteritis)
Giant cell arteritis, inflammation of blood vessel walls, affects 10%-15% of polymyalgia rheumatica patients. Symptoms of giant...
Essential Mixed Cryoglobulinemia
Essential mixed cryoglobulinemia is a condition caused by abnormal blood proteins called cryoglobulins. Symptoms include joint...
Heart Attack Prevention
Heart disease and heart attacks can be prevented by leading a healthy lifestyle with diet, exercise, and stress management....
Bernard-Soulier Disease (Giant Platelet Syndrome)
Bernard-Soulier disease is a rare inherited bleeding disorder caused by a defect in the platelet glycoprotein complex 1b-IX-V....
Treatment & Diagnosis
- Toe Pain
- Hand Pain
- Finger Pain
- Joint Pain
- Arm Pain
- Wrist Pain
- Stiff Neck
- Foot Pain
- Hip Pain
- Shoulder Pain
- Swollen Ankles and/or Swollen Feet
- Elbow Pain
- Jaw Pain
- Unsteady Gait
- Joint Stiffness
- Knee Pain
- Swollen Joints
- Heel Pain
- Neck Pain (Cervicalgia)
- Joint Redness
- Heart Attack in Women
- Sore Throat (Pharyngitis)
- Joint Warmth
- Doctor: Checklist to Take To Your Doctor's Appointment
- Heart Disease
- Rheumatoid Arthritis (RA)
- Systemic Lupus Erythematosus (SLE)
- Chronic Pain
- Psoriatic Arthritis
- Ankylosing Spondylitis (Bechterew's Disease)
- Kawasaki Disease
- Henoch-Schonlein Purpura
- Rheumatoid Arthritis FAQs
- Heart Disease FAQs
- Pain Management Over-The-Counter
- Prescriptions: Complying with the Doctor's Orders
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- Heart Health- Little Aspirin A Day Stops Big Heart Attack!
- Pain (Acute and Chronic)
- Drugs: Buying Prescription Drugs Online Safely
- Drugs: The Most Common Medication Errors
- Medication Disposal
- Dangers of Mixing Medications
- Swine Flu: One New York City Pediatrician's View
- Propofol (Diprivan) Safety
- Is Reye Syndrome Less Common than It Used to Be?
- Why Is It Called Reye's Syndrome?
- Ibuprofen May Block Aspirin's Heart Benefits
- Nosebleeds: First Aid
- Generic Drugs, Are They as Good as Brand-Names?
Medications & Supplements
- Nonsteroidal Antiinflammatory Drugs (NSAIDs)
- naproxen (Aleve, Anaprox, Naprelan, Naprosyn)
- Aspirin vs. Plavix (clopidogrel)
- Drug Interactions
- Drugs: Questions to Ask Your Doctor or Pharmacist about Your Drugs
- Aspirin vs. NSAIDs (Side Effect and Use Differences)
- Aspirin Therapy (Guidelines for Heart Attack and Stroke Prevention)
- Aspirin vs. Aleve (Naproxen)
- OTC Pain Relievers and Fever Reducers
- Aspirin vs. Tylenol (acetaminophen)
- salsalate, Amigesic, Salflex, Argesic-SA, Marthritic, Salsitab, Artha-G
- ticlopidine, Ticlid (discontinued brand in the US)
- Aspirin vs. Eliquis (apixaban)
- choline magnesium salicylate, Trilisate
- dimethyl fumarate (Tecfidera)
- teriflunomide (Aubagio)
- Aspirin vs. warfarin (Coumadin, Jantoven)
- valdecoxib, Bextra
- Aspirin vs. Xarelto (rivaroxaban)
Prevention & Wellness
- Heart Attacks Fall By One-Third Among Older Americans
- Low-Dose Aspirin Doesn't Prolong Survival in Prostate Cancer
- Aspirin Can Help Prevent Colon Cancer, But Many at Risk Don't Take It
- Blood Thinning Drug May Be Safer Option Against Recurrent Stroke
- Will Healthy Seniors Benefit From Daily Aspirin?
- Is Daily Low-Dose Aspirin Really Worth It for Seniors?
- Aspirin, Fish Oil May Not Prevent Heart Trouble in Those Already at Risk
- Daily Low-Dose Aspirin May Be Weapon Against Ovarian Cancer
- Aspirin as Good a Clot Buster as Pricey Drugs After Joint Replacement
- Some Diabetics May Not Benefit From Daily Aspirin
Health Solutions From Our Sponsors
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
FDA Drug Information