[Side Effects of Acetaminophen and their Management].

Acetaminophen, a para-aminohenol derivative, was first clinically used in 1893. In 1980 s, the relevance of aspirin for Reye's syndrome became a problem, then acetaminophen came into use for various kinds of cases such as children, pregnant women and the elderly for pain management or alleviation of fever. However, because acetaminophen has a very weak COX-1 and COX-2 inhibitory effect it has weak or no anti-inflam- matory effect Therefore physicians do not wish to use acetaminophen for management of pain in which in- flammation is thought to be the main mechanism. But recently acetaminophen has become reevaluated as an indication for patients with chronic pain. In 2011, the maximum daily dose of acetaminophen in Japan was increased from 1,500 ng - day-- to 4,000 mg - day-1 (international dosage). As acetaminophen has few side effects of gastrointestinal and renal systems, its use is recommended for the control of long term pain man- agement The side effects of acetaminophen and their management are discussed.