7.5gms in an adult may produce hepatotoxicity. These patients, plus all those for whom an exact amount of ingestion cannot be established with certainty, should have a serum acetaminophen level done 4 hours post ingestion. The clinical course after a toxic ingestion follows 4 stages. Stage 1 occurs 12- 24 hours post ingestion. Symptoms present include nausea, vomiting, diaphoresis, and anorexia.
Children frequently have episodes of vomiting even without toxic levels.
Laboratory studies are typically normal during this time. 24- 48 hours post ingestion. By that time, symptoms have decreased but laboratory abnormalities begin to appear with a rise of SGOT, SGPT, bilirubin, and prothrombin time. 48- 96 hours post ingestion and is when the peak abnormalities are seen. SGOT levels as high as 30,000 may be seen.