Get a useful overview of acetaminophen hepatic metabolism, which occurs through 3 distinct pathways.
As with most medicines acetaminophen is metabolized in the liver this presentation offers a closer look at the mechanisms of that metabolism three different hepatic pathways are involved in acetaminophen metabolism the glue coronoid conjugation pathway accounts for approximately 60% of acetaminophen hepatic metabolism the resultant glue coronoid conjugate
Is non-toxic and is excreted in the urine the sulfate conjugation pathway accounts for approximately 30% of acetaminophen hepatic metabolism the resultant non toxic sulfate conjugate is also excreted in the urine only a small proportion of acetaminophen about five to ten percent is metabolized through the cytochrome p450 to e1 pathway here acetaminophen is
Oxidized to form the reactive intermediate metabolite na pqi na pq i in turn conjugates with judith ion also known as gsh to produce non-toxic myrrh capture ik acid and cysteine metabolites which are excreted in the urine sufficient glutathione is available to conjugate the amount of na pqi produced when acetaminophen is taken at recommended doses however in
The uncommon setting of acute acetaminophen overdose for example ingestion of seven point five to ten grams and eight hours or less the amount of na pqi produced may increase markedly and the amount of glutathione available may become insufficient to conjugate the na p qi it is estimated that when the amount of glutathione is reduced to about thirty percent of
Normal unconjugated na p qi may bind to hepatic cell macromolecules leading to hepatic injury acute acetaminophen overdose can often be managed effectively timely assessment and appropriate monitoring of serum acetaminophen levels as well as selective use and timely administration of the antidote and acetylcysteine can be effective in preventing overdose related
Hepatic injury in summary acetaminophen is metabolized in the liver through three distinct pathways all of which ultimately yield non-toxic metabolites when acetaminophen is taken at recommended doses