Aspirin, or acetylsalicylic acid (ASA) is a salicylate drug, and is generally used as an analgesic (something that relieves pain without producing anesthesia or loss of consciousness) for minor aches and pains, to reduce fever (an antipyretic), and also as an anti-inflammatory drug.
Aspirin has also become increasingly popular as an anti-platelet - used to prevent blood clot formation - in long-term low doses to prevent heart attacks and strokes in high risk patients. Nowadays, aspirin is often given to patients immediately after a heart attack to prevent recurrence or cardiac tissue death.
Contents of this article:
You will also see introductions at the end of some sections to any recent developments that have been covered by MNT's news stories. Also look out for links to information about related conditions.
Fast facts on aspirin
Here are some key points about aspirin. More detail and supporting information is in the main article.
- Aspirin is one of the most widely used medications in the world.
- Aspirin is a derivative of salicylate, which can be found in such plants as willow trees and myrtle
- An ancient Sumer stone table of medical text from the Third Dynasty of Ur - around 3000 BC - mentions willow-tree based remedies.
- Remedies derived from the willow plant were widely used throughout the Roman Empire, among North American tribes and ancient Arab, Aztec and Mayan civilizations.
- Aspirin was the first non-steroidal anti-inflammatory drug to be discovered.
- Apollo Moon astronauts had Aspirin included in their self-medication kits.
- Aspirin interacts with a number of other drugs, including warfarin and methotrexate.
- Side effects of aspirin include nausea and stomach irritation.
What is aspirin?
Aspirin is commonly used to relieve pain, inflammation and fever and prevent clot formation.
Aspirin is a non-steroidal anti-inflammatory drug (NSAID). NSAIDs are medications with analgesic, antipyretic (something that reduces a fever), and in higher doses anti-inflammatory effects. Non-steroidal means they are not steroids, which often have similar effects.
As analgesics, NSAIDs are generally non-narcotic (do not cause insensibility or stupor). The most prominent NSAIDs are aspirin, ibuprofen and naproxen - mainly because most of them are OTC (over-the-counter, no prescription required) medications. Aspirin was the first discovered NSAID.
Aspirin in its present form has been around for over 100 years and is still one of the most widely used medications in the world. It is estimated that approximately 40,000 metric tons of it is consumed annually.
Aspirin is a trademark owned by German pharmaceutical company Bayer; the generic term is acetylsalicylic acid (ASA).
A short history of aspirin
Acetylsalicylic acid (aspirin) is a derivative of salicylate, which can be found in such plants as willow trees and myrtle. Ancient texts dating back as far as 3000 BC have referenced remedies based around willow and myrtle. On many occasions, these plants were used in the treatment of pain, fever and inflammation.
- 1763 - Edward Stone, England, a Church of England rector wrote a letter to the Royal Society which described some of his experiments with willow bark extract to cure ague - a word used to describe intermittent fever, pain, chills and fatigue. He had discovered salicylic acid, the active ingredient in aspirin. Willow bark derived remedies subsequently became much more popular in England than the more expensive Peruvian bark.
- 1828 - Joseph Buchner, a German chemist, managed to obtain what were then considered as fairly pure salicin crystals. Henri Leroux, a French chemist, obtained purer forms the following year.
- 1830 - Johann Pagenstecher, a Swiss pharmacist, said he had discovered a new painkiller which he had isolated from the common remedy of meadowsweet Spiraea ulmaria, which we know today contained salicylic acid, flavone-glycosides, essential oils and tannins.
- 1838 - Raffaele Piria, an Italian chemist, managed to devise a way of obtaining a more powerful acid form of willow extract, which he called salicylic acid. Karl Jacob Lowig, who was trying to isolate the active ingredients in Spiraea, eventually found out that it was the same salicylic acid that Piria had identified.
- 1840-1894 - During this period various forms of salicylate medicines, including salicin, salicylic acid, and sodium salicylate became more widely used by doctors for the treatment of pain, fever and inflammation. However, their gastric irritation side effects were considerable.
- 1897 - The pharmaceutical division of the German company Bayer find the best way of making acetylsalicylic acid (ASA); from salicylic acid refluxed with acetic anhydride (refluxing involves the boiling of a liquid in a vessel attached to a condenser so that the vapors continuously condense for reboiling). Surreptitious testing followed by full trials were conducted, before ASA production began.
- 1915 - Aspirin became available as an OTC (over-the-counter, no prescription required) medication in tablet form.
- 1920s - Aspirin became a commonly used medication for the treatment of neuralgia, lumbago and rheumatism.
- 1948 - A Californian GP (general practitioner, primary care physician) reported that many of his patients who regularly took aspirin had significantly lower rates of heart attacks.
- 1952 - Chewable Aspirin became available.
- 1988 - The FDA (Food and Drug Administration), USA, proposed use of aspirin for reducing risk of recurrent myocardial infarction, heart attack, and preventing first myocardial infarction in patients with unstable angina. The same agency also approved aspirin use for the prevention of recurrent mini-strokes (recurrent transient-ischemic attacks) in men, it also made aspirin standard therapy for men after suffering a stroke.
- 1988 - A study by Dr. Charles Hennekens and team found that aspirin dramatically reduces risk of a first myocardial infection. Hennekens later found the same for cardiovascular disease.
- 1998 - A major study, The Hypertension Optimal Study, published in The Lancet showed that low dose ASA combined with medication for hypertension significantly reduced the risk of myocardial infarction and major cardiovascular events in patients with hypertension.
Therapeutic uses of aspirin
Aspirin is one of the most commonly used drugs for the treatment of mild to moderate pain, as well as migraines and fever. For the treatment of moderate to severe pain it is frequently used along with other opioid analgesic and other non-steroidal-anti-inflammatory drugs.
Below is a list of most therapeutic uses of aspirin:
- Mild to moderate pain
- Moderate to severe pain combined with other medications
- Rheumatic fever (in higher doses)
- Rheumatic arthritis (in higher doses)
- Many other inflammatory joint conditions (in higher doses)
- To inhibit platelet aggregations (blood clot formations) to reduce risk of transient ischemic attacks and unstable angina (in lower doses)
- For the prevention of stroke (in lower doses)
- For the prevention of myocardial infarction in patients with cardiovascular disease. According to researchers from the University of California, San Diego, chewable aspirin is better than other forms.
- In the treatment of pericarditis
- In the treatment of coronary artery disease
- In the treatment of myocardial infarction
- Colorectal cancer - men and women who were diagnosed with colorectal cancer and began regular use of aspirin had a lower risk of overall and colorectal cancer death compared to patients not using aspirin, according to researchers at Massachusetts General Hospital and Harvard Medical School, Boston, MA
- Cancer prevention - taking aspirin in your 40s could cut the risk of cancer developing later in life, according to researchers from the Cancer Research UK Centre for Epidemiology at Queen Mary, University of London, UK.
Aspirin and children
Acetaminophen (paracetamol, Tylenol) and ibuprofen are generally used for children; not aspirin. Aspirin and salicylate NSAID usage in children raises the risk of developing Reye's Syndrome. In some countries, such as the UK, aspirin is only occasionally used in children under specialist supervision for Kawasaki disease and to prevent blood clot formation after heart surgery.
Low-dose aspirin (75mg per day) is used as an antiplatelet medication - to prevent the formation of clots in the blood.
Low-dose aspirin may be given to patients who had:
- A coronary artery bypass graft operation
- A heart attack
- A stroke
- Atrial fibrillation
- Acute coronary syndrome.
The following people may also be given low-dose aspirin if the doctor believes they are at risk of heart attack or stroke:
- Patients with high blood cholesterol levels
- Patients with hypertension (high blood pressure)
- Patients with diabetes
- Some smokers.
The following patients may also be advised to take low-dose aspirin:
- Those with damage to the retina (retinopathy)
- Those with kidney damage (nephropathy)
- Some patients who have had diabetes for over ten years
- Some patients who are taking antihypertensive medications.
In all these cases, low-dose aspirin will be taken daily for the rest of the patient's life.
On the next page, we look at precautions for aspirin use and potential side effects.