Acetaminophen Lab Flashcards
Where is paracetamol metabolised
In the liver
Name 3 pathways involved in acetaminophen metabolism
Glucuronide conjugation
Sulfate conjugation
Cytochrome p450 2e1
What is considered acute acetaminophen overdose
Ingestion of 7.5 - 10g in 8 hours or less
What is the antidote to acetaminophen (overdose)
N-acetylcysteine
What does analgesic-antipyretic mean
Pain medication
What can paracetamol overdose lead to
Liver necrosis and liver failure
What does the metabolism of NAPQI (toxic) deplete
Glutathione stores
What individuals are more sensitive to effects of NAPQI
Patients with chronic liver disease, malnutrition and alcoholism
NAPQI when conjugated with glutathione forms
Non toxic mercapturic acid and cysteine metabolites
What are the four stages of clinical presentation
Nonspecific symptoms
Hepatotoxicity
Maximum hepatotoxicity
Recovery
What is used to assess if patient requires N-acetylcysteine
Rumack-Matthew Nomogram
What is the rumack matthew nomogram based on
The half life of acetaminophen being 4 hours or greater
When can charcoal be used to treat acetaminophen overdose patients
Patients with large ingestions presenting within 2 hours
Ipecac use
Used to induce vomiting
(risk of aspiration and causing neuritis)
Rumack-Matthew nomogram scale
Above line = possible toxicity, start NAC
Below the line = likely to develop hepatic toxicity but do not need NAC therapy
Between lines = probable and in US start NAC
