Aspirin

Aspirin (also known as acetylsalicylic acid) is a drug. It is most commonly used as a painkiller and to treat headaches, toothache, and period pain. It is also used to reduce fever, flu-like symptoms or colds, and inflammation.^[3] It usually starts working 20-30 minutes after taking it.

Aspirin
INN: acetylsalicylic acid

Clinical data
Pronunciation	acetylsalicylic acid /əˌsiːtəlˌsælɪˈsɪlɪk/
Trade names	Bayer Aspirin, many others
Synonyms	2-acetoxybenzoic acid acetylsalicylate acetylsalicylic acid O-acetylsalicylic acid, Aspirin (BAN UK), Aspirin (USAN US)
AHFS/Drugs.com	Monograph
MedlinePlus	a682878
License data	EU EMA: by INN US FDA: Aspirin
Pregnancy category	AU: C
Routes of administration	by mouth, rectal, lysine acetylsalicylate may be given intravenously or intramuscularly
ATC code	A01AD05 (WHO) B01AC06 (WHO), N02BA01 (WHO)
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
Bioavailability	80–100%[1]
Protein binding	80–90%[2]
Metabolism	Liver, (CYP2C19 and possibly CYP3A), some is also hydrolysed to salicylate in the gut wall.[2]
Elimination half-life	Dose-dependent; 2 h to 3 h for low doses (100 mg or less), 15 h to 30 h for large doses.[2]
Excretion	Urine (80–100%), sweat, saliva, feces[1]
Identifiers
IUPAC name 2-Acetoxybenzoic acid
CAS Number	50-78-2 Y
PubChem CID	2244
IUPHAR/BPS	4139
DrugBank	DB00945 Y
ChemSpider	2157 Y
UNII	R16CO5Y76E
KEGG	D00109 Y
ChEBI	CHEBI:15365 Y
ChEMBL	ChEMBL25 Y
PDB ligand	AIN (PDBe, RCSB PDB)
ECHA InfoCard	100.000.059
Chemical and physical data
Formula	C9H8O4
Molar mass	180.158 g/mol
3D model (JSmol)	Interactive image
Density	1.40 g/cm3
Melting point	136 °C (277 °F)
Boiling point	140 °C (284 °F) (decomposes)
Solubility in water	3 mg/mL (20 °C)
SMILES O=C(C)Oc1ccccc1C(=O)O
InChI InChI=1S/C9H8O4/c1-6(10)13-8-5-3-2-4-7(8)9(11)12/h2-5H,1H3,(H,11,12) Y Key:BSYNRYMUTXBXSQ-UHFFFAOYSA-N Y
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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^[4]

Aspirin is one of the most-used medical drugs in the world and is on the World Health Organization's List of Essential Medicines^[5]

Humans (children) under 16^[3] (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 side-effects to this drug. For example, large amounts can damage the kidneys.

People with lung, kidney disease, gout, hyperuricemia (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 naproxen should not take aspirin. People with asthma, where attacks are brought about by aspirin, should avoid using any anti-inflammatory drugs based on it.

Aspirin was invented in Germany in 1897. Bayer has a trademark on the brand name "aspirin" in 80 countries. But in other countries, "aspirin" is the common name for the drug.

Related pages

• Acetaminophen (Tylenol, paracetamol)
• ibuprofen