Pathways of acetaminophen metabolism at therapeutic versus toxic doses

We have updated the acetaminophen pharmacokinetic pathway, which depicts the metabolism at therapeutic doses. In addition we added a new pathway illustrating the metabolism of acetaminophen at toxic doses.

Acetaminophen (paracetamol) is widely used for its analgesic and antipyretic properties. Acetaminophen is mostly converted by glucuronidation and sulfation. A minor fraction of acetaminophen is oxidized to a reactive metabolite NAPQI, which is primarily responsible for acetaminophen-induced hepatotoxicity. A higher proportion of the drug gets oxidized at toxic doses leading to an increased risk of hepatotoxicity. 

For more information on differences in the PK of acetaminophen between therapeutic vs toxic doses go to Acetaminophen Pathway (therapeutic doses), Pharmacokinetics and Acetaminophen Pathway (toxic doses), Pharmacokinetics.

View all pathways at PharmGKB.