Ch. 143 Acetaminophen Toxicity Flashcards
What is the international name for acetaminophen?
Paracetamol
How does acetaminophen work?
Inhibits prostaglandin E2 leading to antipyresis and analgesia
How does NAC work?
Precursor to glutathione and also an alternative to glutathione to reduce the amount of NAPQI
It also helps to prevent the formation of NAPQI in the first place and can even have beneficial effects when there is liver failure but no longer any detectable serum levels of acetaminophen.
What are the early symptoms of acetaminophen overdose?
Early in the course the patient is usually asymptomatic. Liver failure doesn’t start until after 8-36 hours.
What is the time course for liver injury to first begin and what lab value is first seen? What are the first symptoms seen at this point? What are the lab abnormalities seen after the first abnormality?
8-36 hours after ingestion will start to see elevations of AST. Later, ALT, PT, and bilirubin begin to rise.
Pt may start to have RUQ, vomiting, and jaundice
At what time point is maximal liver injury usually complete?
2-4 days
What signs, symptoms, and effects are seen after fulminant liver failure?
Metabolic acidosis, coagulopathy, hepatic encephalopathy, cerebral edema, hemorrhage, multi-system organ failure, renal failure, ARDS, sepsis
What is the general time course of acetaminophen toxicity and general symptoms at each stage?
1) Pre-injury: first ~12 hours, nausea, vomiting, anorexia
2) Liver injury: 8-36 hours, RUQ pain, vomiting, AST begins to rise
3) Max injury: 2-4 days, hemorrhage, coagulopathy, encephalopathy, cerebral edema, organ failure, ARDS, SIRS
4) Recovery: >4 days, symptoms resolve and labs return to normal
If patients survive the liver injury, what are the long-term effects on the liver?
There are no known long-term effects on the liver after it recovers
