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Pharmacologic Class:
Non-narcotic analgesic, antipyretic, anti-inflammatory agent.

Brand Names/AKA:
Acetylsalicylic acid, ASA or Aspirin

It is commonly used to treat aches of the head, joints, and muscles, and to prevent coronary and cerebrovascular events. It is also used to reduce fevers, inflammations, and swelling. For this reason it is used as a treatment for rheumatoid arthritis, rheumatoid fever, and mild infections. It is sometimes used as an additive in food, animal feed, drugs, and cosmetics.

Creates antipyretic effects by acting on the hypothalamus to promote sweating and dilation of peripheral blood vessels to dissipate heat. Anti-inflammatory effects are believed to be the result of cyclo-oxygenase inhibition, which decreases synthesis of prostaglandin (which is believed to be part of the inflammation process).

It should not be used by children with viral illnesses or a risk of Reye's Syndrome, or by people with gout or active peptic ulcer disease, or by people who have a hypersensitivity to it. It causes inhibition of platelet aggregation for the lifetime of the platelets exposed (8-10 days). Also, the dust can cause irritation in the eyes and respiratory tract.

ASA should probably not be mixed with strong oxidising agents, strong bases, strong acids, iodides, iron salts, quinine salts, acetazolamide, ethyl alcohol, recombinant alteplase, oral anticoagulants, antirheumatics, beta-adrenergic blocking agents, activated charcoal, corticosteroids, dipyridamole, furosemide, garlic, ginko biloba, ginseng, heparin, oral hypoglycemics, indomethacin, insulin, methionine, methotrexate, nitoglycerin, phenylbutazone, phenytoin, probenecid, spironolactone, sulfinpyrazone, or sulfonamides. YMMV, IANAD.

Additional Information:
Acetylsalicylic Acid is an acetyl derivative of salicylic acid. It is a white, crystalline, weakly acidic substance. Dosages of greater than 10mg/dl provide an analgesic effect, while doses larger than 50mg/dl are used for anti-inflammatory effects. Doses above 80 are considered overdoses, and can cause tinnitus, hyperventilation, fever, metabolic acidosis, coma, cardiovascular instability, renal failure, and respiratory failure. In some cases, acetaminophen (Tylenol) is substituted for ASA.

Sources: http://www.chemicalland21.com/arokorhi/lifescience/phar/ACETYLSALICYLIC%20ACID.htm http://ptcl.chem.ox.ac.uk/MSDS/AC/acetylsalicylic_acid.html http://www.fpnotebook.com/PHA41.htm http://www.nursespdr.com/members/database/ndrhtml/acetylsalicylicacid.html
Thanks to ponder for a correction to my ASCII art.