Acetaminophen NAC IV Dosing
N-acetylcysteine dosing for acetaminophen poisoning.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Body weight
- 120
- IV NAC regimen
- Three-bag (21-hour) -- 150, 50, 100 mg/kg
Result: NAC three-bag (21 h), dose fixed at 100 kg and above (entered 120 kg): bag 1 15000 mg in 200 mL over 1 h, bag 2 5000 mg in 500 mL over 4 h, bag 3 10000 mg in 1000 mL over 16 h (total 30000 mg).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Three-bag (21 h)
- 150 mg/kg over 1 h, then 50 mg/kg over 4 h, then 100 mg/kg over 16 h (300 mg/kg total).
- Two-bag (label alternative)
- 200 mg/kg over 4 h, then 100 mg/kg over 16 h; for 41 kg and over only. Not known to be comparable to the three-bag regimen in preventing hepatotoxicity.
- 100 kg and above
- The dose is fixed: 15,000 / 5,000 / 10,000 mg (three-bag) or 20,000 / 10,000 mg (two-bag).
- Under 5 kg
- Not studied; the label gives no dose.
What you enter
- Body weight (kg)
- IV NAC regimen
How this is calculated
Citation
ACETADOTE (acetylcysteine) injection prescribing information, sections 2.4-2.5, Tables 2-3 (label version 17, revised April 2025): three-bag and two-bag regimens, diluent volumes, fixed dose at 100 kg and above. Three-bag regimen first described by Prescott LF, et al. BMJ. 1979;2(6198):1097-1100. Read the sources: Acetadote label ↗, Prescott 1979 ↗, MHRA 2017 (UK posology) ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.