Acetaminophen 1150 mg Ingestion: Safety Assessment
A single dose of 1150 mg of acetaminophen (Tylenol) is not a concern for toxicity in adults and does not require medical intervention or monitoring.
Understanding Acetaminophen Dosing and Toxicity Thresholds
Acetaminophen toxicity risk is dose-dependent and follows these general parameters:
Safe therapeutic dosing:
- Maximum single dose: 1000 mg (typically)
- Maximum daily dose: 3000-4000 mg (depending on formulation)
- Toxic threshold: Generally requires >7500 mg (7.5 g) in a single ingestion 1
Risk assessment for 1150 mg ingestion:
- Exceeds standard single dose by only 150 mg
- Well below toxic threshold (approximately 15% of minimum toxic dose)
- For toxicity risk, most adults must ingest about 12g or more 2
Clinical Decision Making
The FDA and clinical guidelines indicate that hepatotoxicity risk begins at much higher doses:
- Acute ingestion of ≥150 mg/kg (or approximately 10.5 g for a 70 kg adult) is the threshold where hepatotoxicity becomes a concern 3
- For an acute overdose requiring treatment, the history must suggest ingestion of >7.5 g in the previous 24 hours 4
Special Considerations
While 1150 mg is safe for most adults, certain populations may have increased risk factors:
- Patients with risk factors for increased susceptibility:
- Chronic alcoholism
- Malnutrition
- Liver disease
- Concurrent use of CYP2E1 enzyme-inducing medications 1
However, even in patients with chronic liver disease, standard therapeutic doses of acetaminophen (including a single 1150 mg dose) have not shown increased risk of hepatotoxicity 5.
When Medical Attention Is Warranted
Medical evaluation would be recommended for:
- Single ingestions exceeding 7.5 g
- Repeated supratherapeutic ingestions exceeding 4 g daily
- Development of symptoms such as nausea, vomiting, abdominal pain, or jaundice
Conclusion on This Specific Scenario
The 1150 mg dose described is only slightly above the standard maximum single dose (1000 mg) and significantly below any dose that would warrant medical concern or intervention. The National Comprehensive Cancer Network (NCCN) guidelines note that acetaminophen toxicity becomes a concern at much higher doses than what is described in this scenario 4.
If this represents a one-time ingestion with no other acetaminophen intake within the same day, there is no need for medical intervention, laboratory testing, or administration of N-acetylcysteine.