acetaminophen, an analgesic and fever-reducing medicine similar in effect to aspirin. It is an active ingredient in many over-the-counter medicines, including Tylenol and Midol. Introduced in the early 1900s, acetaminophen is a coal tar derivative that acts by interfering with the synthesis of prostaglandins and other substances necessary for the transmission of pain impulses. Although its action is similar to that of aspirin, it lacks aspirin's anti-inflammatory and blood-thinning effects, is less irritating to the stomach, and can be used by people who are allergic to aspirin. Heavy use, however, has been linked to an increased incidence of liver failure, especially in heavy drinkers of alcoholic beverages and in those who are not eating enough, and overdose, especially in children, can be fatal.

also called paracetamol

Drug used to relieve mild headache or muscle and joint pain and to reduce fever. An organic compund, it relieves pain by inhibiting prostaglandin synthesis in the central nervous system and reduces fever by acting on the temperature-regulating centre of the brain. Unlike aspirin, it has no anti-inflammatory effect. It also is much less likely to irritate the stomach and cause peptic ulcers, is not linked with Reye syndrome, and can be taken by persons using anticoagulants or allergic to aspirin. Overdosages can cause fatal liver damage. Common brand names around much of the world are Tylenol and Panadol. Seealso ibuprofen.

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