Aspirin

At one time aspirin was commonly used to control fever and pain due to flu or the common cold. However because there appears to be a connection between aspirin and Reyes syndrome[?], aspirin is no longer used to control flu-like symptoms. Aspirin affects blood platelets[?], giving an inhibitory affect on blood clotting[?], making it useful for preventing heart attacks. There is considerable active research into the effects of long-term taking of low-dose aspirin, which appears to have a protective effect against gastric cancers. Its primary undesirable side effects are gastrointestinal distress (including stomach bleeding) and tinnitus.

Aspirin was the first discovered member of the class of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs), not all of which are salicylates, though they all have similar effects and a similar action mechanism.

History

Hippocrates, a Greek for whom the Hippocratic Oath is named, wrote about a bitter powder extracted from willow bark that could ease aches and pains and reduce fevers as long ago as the fifth century B.C. It is also mentioned in texts from ancient Sumeria, Egypt and Assyria. Native American Indians used it for headaches, fever, sore muscles, rheumatism, and chills. The Reverend Edmund Stone[?], a vicar from Chipping Norton in Oxfordshire England, noted in 1763 that the bark of the english willow was effective in reducing a fever, but his reasoning for that was very much in error.

The active extract of the bark, called salicin[?], after the latin name for the white willow (Salix alba), was isolated to its crystaline form in 1828 by Henri Leroux[?], a French pharmacist, and Raffaele Piria[?], an Italian chemist, then succeeded in splitting it up to obtain the acid in its pure state. Salicin is highly acidic when in a saturated solution with water (pH = 2.4), and is called salicylic acid for that reason. Salicylic acid's systematic name is 2-hydroxybenzoic acid.

This chemical was also isolated from meadowsweet flowers (latin name spiraea[?]) by German researchers in 1839, and while somewhat effective, also caused many digestive problems including irritated stomach and diarrhea, and can cause death in higher doses. In the 1897, Felix Hoffmann[?], a chemist working for Friedrich Bayer[?] & Co, in Germany derivatized one of the hydroxyl functional groups in salicylic acid with an acetyl group (forming the acetyl ester) which greatly reduced the negative effects. The new drug, named a- (for the acetyl group) -spir- (for the flower) -in (a common ending for drugs at the time), had fewer side effects and was more effective than salicin or salicylic acid. This was the first synthetic drug, not a copy of something that existed in nature, and the start of the pharmaceuticals industry. Bayer registered aspirin as a trademark on March 6, 1899.

The name "Aspirin" is still a trademark in some countries over a hundred years since its discovery. However, Bayer lost the trademark in the United States and some other countries as part of World War I reparations.

How it works

In a piece of research for which he was awarded both a Nobel prize and a knighthood, John Vane[?], who was then employed by the Royal College of Surgeons[?] in London, showed in 1971 that aspirin suppresses the production of local hormones known as prostaglandins[?]. Cyclooxygenase 2[?], an enzyme which participates in the production of some prostaglandins, is disabled when Aspirin attaches to it.

Prostaglandins are normally produced in the body to transmit the pain information to the brain. Additionally those prostaglandins are responsible for the accumulation of platelets that form blood clots[?]. Heart attacks are primarily caused by blood clots, and their reduction with the introduction of small amounts of aspirin has been seen to be an effective medical intervention. The side effect of this is that the ability of the blood in general to clot is reduced, and excessive bleeding may result from the use of aspirin.

External links

• http://www.bayeraspirin.com
• http://almaz.com/nobel/medicine/aspirin
• http://chemed.chem.purdue.edu/genchem/topicreview/bp/1biochem/research7