Aspirin

Aspirin
INN: acetylsalicylic acid
Clinical data
Pronunciationacetylsalicylic acid /əˌsiːtəlˌsælɪˈsɪlɪk/
Trade namesBayer Aspirin, many others
Other names2-acetoxybenzoic acid
acetylsalicylate
acetylsalicylic acid
O-acetylsalicylic acid, Aspirin (BAN UK), Aspirin (USAN US)
AHFS/Drugs.comMonograph
MedlinePlusa682878
License data
Pregnancy
category
  • AU: C
Routes of
administration
by mouth, rectal, lysine acetylsalicylate may be given intravenously or intramuscularly
ATC code
Legal status
Legal status
  • AU: S2 (Pharmacy medicine) except when given intravenously (in which case it is schedule 4), used in animal medicine (schedule 5/6) or when the dose is higher than usual.
  • UK: General sales list (GSL, OTC)
  • US: OTC
Pharmacokinetic data
Bioavailability80–100%
Protein binding80–90%
MetabolismLiver, (CYP2C19 and possibly CYP3A), some is also hydrolysed to salicylate in the gut wall.
Elimination half-lifeDose-dependent; 2 h to 3 h for low doses (100 mg or less), 15 h to 30 h for large doses.
ExcretionUrine (80–100%), sweat, saliva, feces
Identifiers
  • 2-Acetoxybenzoic acid
CAS Number
PubChem CID
IUPHAR/BPS
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
PDB ligand
CompTox Dashboard (EPA)
ECHA InfoCard100.000.059 Edit this at Wikidata
Chemical and physical data
FormulaC9H8O4
Molar mass180.158 g/mol
3D model (JSmol)
Density1.40 g/cm3
Melting point136 °C (277 °F)
Boiling point140 °C (284 °F) (decomposes)
Solubility in water3 mg/mL (20 °C)
  • O=C(C)Oc1ccccc1C(=O)O
  • InChI=1S/C9H8O4/c1-6(10)13-8-5-3-2-4-7(8)9(11)12/h2-5H,1H3,(H,11,12) checkY
  • Key:BSYNRYMUTXBXSQ-UHFFFAOYSA-N checkY
  (verify)

Aspirin (also known as acetylsalicylic acid) is an over-the-counter medication. It is most commonly used as a painkiller and to treat headaches, toothache, and minor aches and pains. It is also used to reduce fever, flu-like symptoms, and inflammation. It usually starts working 20-30 minutes after taking it.

It has an anti-platelet effect, which means it reduces the number of platelets in the blood, which in turn reduces blood clotting. Because of this, it is used to treat heart attacks. Low-dose aspirin is sometimes prescribed to people who are at a greater risk of heart attacks or stroke.

Aspirin is one of the most-used medical drugs in the world and is on the World Health Organization's List of Essential Medicines.

Humans (children) under 16 (used to be 12 and then 14) can develop Reye's syndrome from using aspirin. This causes the liver to become fatty and not work properly. The brain may also become enlarged. Reye's Syndrome can be fatal or lead to permanent brain damage, but most children survive with treatment.

There are possible adverse effects to this drug. For example, large amounts can damage the kidneys and the stomach lining, contributing to ulcers.

People with lung, kidney disease, gout, high amounts of uric acid in the blood, hemophilia, diabetes, or high blood pressure should not take aspirin except on the advice of a qualified medical professional.

People who are allergic to aspirin, or to ibuprofen or certain other nonsteroidal anti-inflammatory medications (NSAIDs) should not take aspirin.

People with asthma triggered by aspirin should avoid using any anti-inflammatory drugs with salicylic acid.

Aspirin was invented in Germany in 1897, and was patented by Bayer in March, 1899. During World War I, Bayer's U.S. assets, including the trademark for Aspirin, were seized, and the word “Aspirin” lost its trademark status.

In September 1994, Bayer spent a billion American dollars to re-acquire their Aspirin trademark, lost since the Treaty of Versailles in 1919, by purchasing Sterling Winthrop’s over-the-counter medication business in the United States, Canada and Puerto Rico from Britain’s SmithKline Beecham.

Bayer currently holds the trademark on the brand name "aspirin" in over 80 countries.

Regardless of trademark, in all other countries, as in the countries where Bayer holds the trademark, "aspirin" is considered the common name for the drug.

References

  1. 1 2 "Zorprin, Bayer Buffered Aspirin (aspirin) dosing, indications, interactions, adverse effects, and more". Medscape Reference. WebMD. Archived from the original on 7 April 2014. Retrieved 3 April 2014.
  2. 1 2 3 Brayfield, A, ed. (14 January 2014). "Aspirin". Martindale: The Complete Drug Reference. Pharmaceutical Press. Retrieved 3 April 2014.
  3. 1 2 "About aspirin for pain relief". nhs.uk. 2021-09-17. Retrieved 2024-05-26.
  4. ↑ "Is low-dose aspirin safe for you?". Harvard Health. 2012-10-01. Retrieved 2026-08-02.
  5. ↑ Organization, World Health (2023). "The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023)". WHO. 23. Archived from the original on 2025-05-05. Retrieved 2024-05-26.
  6. ↑ Editors, HISTORY com (2009-11-24). "Bayer patents aspirin | March 6, 1899". HISTORY. Retrieved 2026-08-02. {{cite web}}: |last= has generic name (help)
  7. ↑ "'Genericide': Brands destroyed by their own success". BBC News. 2014-05-27. Retrieved 2026-08-02.
  8. ↑ Jones, Michael (2024-04-24). "Genericide: The Case of Aspirin". Jones IP Law. Retrieved 2026-08-02.
  9. ↑ "German Firm to Reclaim Bayer Aspirin Name : Drugs: It will acquire Sterling Winthrop's over-the-counter business and recover the rights it lost after WWI". Los Angeles Times. 1994-09-13. Retrieved 2026-08-02.