Rumack-Matthew Nomogram
Determines need for N-acetylcysteine (NAC) treatment following paracetamol (acetaminophen) overdose based on serum level and time post-ingestion
Score interpretation
Serum level falls below the Rumack-Matthew treatment line for the given time post-ingestion.
→ NAC not indicated based on nomogram. Supportive care; reassess if time of ingestion uncertain or staggered overdose suspected.
Serum level is at or above the treatment line — significant hepatotoxicity risk without treatment.
→ Start N-acetylcysteine immediately. IV NAC: 200 mg/kg over 4h, then 100 mg/kg over 16h. Involve Poisons Information (UK: 0344 892 0111). Monitor LFTs, INR, creatinine, paracetamol levels.
Interpretation bands for the Rumack-Matthew. Apply clinical judgement and local guidance.
References
- Rumack BH, Matthew H. Acetaminophen poisoning and toxicity. Pediatrics. 1975;55(6):871–876.
- TOXBASE / NPIS. Paracetamol Overdose Treatment Guidelines. 2023.
Related
Curated clinical cross-links plus same-class fallbacks.
- Acetylcysteine (N-acetylcysteine — Paracetamol Overdose) · Mucolytic / Hepatoprotective Antidote
- Acetylcysteine (N-acetylcysteine — NAC) · Antidote — paracetamol overdose / Hepatoprotectant
- Acetylcysteine · Mucolytic / Paracetamol overdose antidote
- Dobutamine (Acute HF / Stress Echo) · Inotrope / Acute Heart Failure
- Milrinone · Inodilator / Acute Heart Failure
- Vericiguat · Heart Failure
- Difficult Airway Algorithm (DAS) · DAS 2015; Royal College of Anaesthetists
- Major Haemorrhage Protocol · NICE NG24; UK MHP guidelines
- New-Onset Atrial Fibrillation · ESC 2020 AF Guidelines; NICE NG196
- Hypertensive Emergency · ESC/ESH 2018 Hypertension Guidelines; NICE NG136
- Bradycardia Management · Resuscitation Council UK ABCDE; ESC 2021 Pacing Guidelines
- Ventricular Tachycardia / Fibrillation · Resuscitation Council UK ACLS; ESC 2022 Ventricular Arrhythmia Guidelines
Featured in these MRCEM clinical pathways
The Rumack-Matthew is covered in detail — with RCEM/NICE evidence base, indications and pitfalls — in the following exam-focused pathways on our sister siteReviseMRCEM.
MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.