Severity of acetaminophen intoxication

The Rumack-Matthews nomogram summarizes the relationship between plasma acetaminophen concentration (in µg/mL or µmol/L), the time after drug ingestion, and the risk of hepatic toxicity. The thick diagonal line of possible hepatic toxicity represents a 25 percent likelihood of disease. A relatively low level (such as 10 µg/mL) is safe soon after ingestion, but associated with appreciable risk at 24 hours since it reflects a high initial load which has now distributed into the tissues.