Acetaminophen can be one of the most dangerous drugs in overdose, as the toxic dose of acetaminophen is 250 mg/kg

There are 4 stages of acetaminophen overdose:

• Stage 1 from 0-24 hours when labs may be normal but the patient has nonspecific symptoms such as nausea, vomiting, and fatigue
• Stage 2 from 24-72 hours when labs may be normal or be trending upward but the patient is asymptomatic
• Stage 3 from 72-96 hours when significant metabolic derangement can occur such as profound metabolic acidosis, florid liver failure, and AKI.
• Stage 4 takes place only if you are able to get them through the acute illness precipitated in Stage 3 when hopefully recovery takes place, though there is no guarantee of liver recovery