Aspirin is the drug most widely used as an analgesic, or pain reliever; antipyretic, or fever reducer; and antiinflammatory
agent. Its activity is based on chemicals called salicylates, derived from willow and other plants and known for their medicinal properties since ancient times. Modern aspirinÑacetylsalicylic acidÑwas synthesized in the laboratory in the late 19th century and introduced into widespread medical use in 1899. Since then it has become the standard by which all other analgesics and antipyretics are measured.
Aspirin is most effective in relieving slight to moderately severe pain, particularly headache, muscle aches, and joint pains. It is less effective against deep-seated pain originating in internal organs. Because it suppresses inflammatory processes while relieving pain, it is still the treatment of choice for arthritis and related disorders. The major therapeutic effects of aspirin involve the inhibition of the synthesis of
prostaglandins, fatty acids with hormonelike functions. Certain prostaglandins form end-products responsible for fever, inflammation, platelet aggregation, controlling blood flow, and protecting the stomach lining. By blocking the production of these prostaglandins, aspirin can reduce fever and prevent platelets from forming blood clots. Aspirin has been proved to decrease further heart attacks in patients who have had one heart attack and in patients with an unstable pattern of angina. It is also recommended for patients with minor strokes and transient ischemic attacks.
Aspirin is considered a relatively safe drug. Its chief drawback is that it can irritate the lining of the stomach and cause bleeding. This is of concern for people with ulcers, as well as arthritis patients who need to take the drug on a regular basis. Coated aspirin is gentler on the stomach. Some people are allergic to aspirin; this allergy is
associated with asthma and nasal polyps. In large doses aspirin is toxic, causing kidney damage and, in severe cases, death. Aspirin should never be given to children with viral diseases such as chicken pox or influenza. Such use has been associated with the sometimes-fatal Reye syndrome.