Aspirin, also known as acetylsalicylic acid, is one of the most commonly used drugs in the world. Chemists classify aspirin in a group of chemical compounds called salicylates. It is a white, odorless powder with a bitter taste. Aspirin helps relieve pain, lowers fever arising from infections, and helps reduce inflammation due to illness or injury. It also interferes with blood clotting, and thus it is useful in preventing heart attacks, strokes, and other disorders that involve blood clots.
Aspirin is relatively safe when taken at the recommended dosage. However, it can irritate the stomach lining and cause stomach bleeding, a serious side effect in some people, particularly the elderly. Children with chickenpox or influenza should not take aspirin. Its use during such viral illnesses is associated with a serious complication called Reye’s syndrome (see Reye’s syndrome).
How aspirin works.
Aspirin is one of a class of drugs called nonsteroidal anti-inflammatory drugs (NSAID’s). These drugs include other pain relievers, such as ibuprofen. NSAID’s work mainly by blocking the formation in the body of prostaglandins, biochemical compounds similar to hormones. Aspirin inactivates two enzymes, cyclooxygenase-1 and cyclooxygenase-2, that are necessary for the formation of prostaglandins.
Aspirin’s reactions with the two enzymes have different effects in the body. When aspirin blocks cyclooxygenase-1, the main effects are reduced blood clotting and irritation of the stomach lining. In contrast, the inactivation of cyclooxygenase-2 reduces fever and inflammation. By the late 1990’s, scientists had developed new drugs called COX-2 inhibitors that act only on cyclooxygenase-2. These so-called superaspirins, such as Celebrex, relieve pain and reduce inflammation and fever without the stomach irritation that aspirin can cause. However, scientists have found that high dosages of these drugs may increase the risk for heart attack and stroke. Medical experts recommend that people consult with a physician before taking these medications.
Health benefits.
Many doctors advise their adult patients to take one aspirin tablet a day to reduce the risk of heart attacks and strokes. Scientists also have observed that people who use aspirin regularly have a lower incidence of breast, colon, and rectal cancer. They believe that aspirin’s effects on the cyclooxygenase-2 enzyme block inflammation and other processes necessary for cancer to develop. Scientists are investigating other potential health benefits of aspirin. However, people should use aspirin to prevent disease only under the care of a physician.
History.
For centuries, people used willow bark to relieve pain and fever. The bark contains a chemical that the body converts to a salicylate. Charles F. Gerhardt, a French chemist, first made acetylsalicylic acid in a laboratory in 1853. In 1897, the German chemist Felix Hoffmann found a new way to develop the compound while working for the chemical company Bayer. Bayer began marketing acetylsalicylic acid as a drug, and gave it the name aspirin.
