Acetaminophen Toxicity

In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan.


Acetaminophen (N-acetyl-para-aminophenol, paracetamol, APAP) toxicity is common primarily because the medication is so readily available, and there is a perception that it is very safe. More than 60 million Americans consume acetaminophen on a weekly basis. Acetaminophen is used in many products in combination with other preparations, especially with opioids and diphenhydramine. Many people are not aware that it is contained in these combination medications.

Acetaminophen is an antipyretic analgesic with a mechanism of action different from NSAIDs. Its mode of action is not clearly understood, but it appears to inhibit cyclooxygenase (COX) in the brain selectively. This results in its ability to treat fever and pain. It may also inhibit prostaglandin synthesis in the central nervous system (CNS). Acetaminophen directly acts on the hypothalamus producing an antipyretic effect.

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