Mild nausea and vomiting/malaise
Hypokalemia (associated with  high 4-hr level)
Massive Ingestion (>500 mg/kg) may present with acidemia, coma, hemodynamic changes shortly after ingestion and prior to hepatic necrosis  
Improvement in symptoms
RUQ abdominal pain
Elevated transaminases
Elevated bilirubin, PT (if severe)
Recurrence of nausea and vomiting
Acute liver necrosis → liver failure
Jaundice
Coagulopathy
Encephalopathy (esp with massive ingestions)
Acute renal failure (1-2%; usually after hepatic failure is evident)
Pancreatitis (rare)
Clinical improvement and recovery (7-8 d) OR
Deterioration to multi-organ failure and death OR
Continued deterioration
Acetaminophen toxicity
Acetaminophen toxicity 
Mescaline toxicity
Viral hepatitis
Cocaine toxicity
Hepatitis A
Carbamate toxicity
Hepatitis B