ACETAMINOPHEN

drug that is used as an alternative to aspirin to relieve mild pain, such as tension headache and pain in joints and muscles, and to reduce fever. It is formed in the body as a metabolite of acetanilid or phenacetin, which were formerly common drugs, and is responsible for their analgesic effects. Acetaminophen relieves pain by raising the body's pain threshold, and it reduces fever by its action on the temperature-regulating centre of the brain, though the drug's particular modes of action remain unclear. Acetaminophen is much less likely to cause gastrointestinal side effects than aspirin, but overdosages of it can cause fatal liver damage. Unlike aspirin, acetaminophen has no anti-inflammatory effect. For prolonged use, aspirin and sodium salicylate are considered safer.