Notice: this content is AI-generated and has not yet been fully reviewed by the author. Do not rely on it for patient care — always verify against the linked guidance and your seniors.
A revision walkthrough — for learning, not live patient decisions. In real practice, poisoning is managed with TOXBASE, NPIS and your seniors. Start the walkthrough
● worked example · learn the approach

Overdose & poisoning

Learn the general approach to poisoning, step by step. Support the patient, identify the toxin, and treat with TOXBASE and NPIS behind you. Built for revision, not live patient decisions.

1

Settle them, and check the basics

support first, then identify

Red flags — what each should make you think

Reduced GCS / airway at riska CNS depressant Pinpoint pupils, slow breathingopioid toxicity Wide QRS or arrhythmia on ECGtricyclic / sodium-channel blocker SeizuresTCA, tramadol and others Agitation, hyperthermia, sweatingserotonergic / sympathomimetic Unknown ingestion + unstabletreat, and call NPIS
🩺
Pearl

Treat the patient, not the poison. Most poisoning is managed with good supportive care — airway, breathing, circulation — while you work out what they took. Check TOXBASE for every case and call the National Poisons Information Service if you're unsure.

Your first moves

  • A–EAssess A–E, protect the airwaya reduced GCS is the main early danger
  • gluBlood glucose + temperatureboth are reversible and easily missed
  • ♥12-lead ECGQRS and QT tell you about cardiotoxicity
  • ✚Bloods incl timed levelsparacetamol & salicylate at 4h, U&E, LFT, VBG
  • TBCheck TOXBASE / call NPISfor the specific risk assessment and antidote
  • RxConsider the antidotewhere there's a specific one — see step 3
2

Understand what was taken

the risk assessment

The questions that drive the plan

  • What — drug(s), and any co-ingestants (including alcohol)
  • How much — number of tablets / volume, and the preparation
  • When — timing decides when levels are valid and when to act
  • Why — intentional or accidental; a compassionate mental-health assessment is part of care
  • Toxidrome — do the signs fit a pattern (opioid, anticholinergic, sympathomimetic)?

Then risk-assess on TOXBASE using the agent, dose and timing — it gives the specific management and observation period.

Work A–E — assess and act as you go

AAirway. A reduced GCS threatens the airway.protect the airway; anaesthetics if GCS ≤8
BBreathing. A low respiratory rate suggests opioids or sedatives.oxygen; consider naloxone if opioid toxicity
CCirculation. ECG for a wide QRS (TCA) or arrhythmia; check BP.IV access, fluids, treat cardiotoxicity per TOXBASE
DDisability. GCS, pupils (pinpoint = opioid), glucose.correct glucose; reassess consciousness
EExposure. Temperature (hyper- or hypothermia), patches, injection sites.remove patches; active cooling/warming if needed
3

The key toxins to know

tap to open each

What points toward it, what would rule it in, and how it's managed — always TOXBASE-guided.

The whole person, not just the poison

Intentional overdose needs a compassionate mental-health assessment once medically stable, and safeguarding should always be considered. Care for the reasons behind it, not only the ingestion.

4

Investigate — what to order, when, and what it tells you

timing matters

Timed drug levels

When
Paracetamol and salicylate levels at 4 hours from ingestion (or per the staggered pathway).
Tells you
Whether treatment (e.g. NAC) is needed — the timing is what makes the level interpretable.

ECG

When
Every significant overdose.
Tells you
QRS width (TCA), QT interval, arrhythmia.

Blood gas & bloods

VBG/ABG
Acid-base pattern, lactate.
Bloods
U&E, LFT, glucose; osmolar gap if a toxic alcohol is suspected.

TOXBASE / NPIS

Always
The definitive source for agent-specific risk and management.
NPIS
Call for complex, severe or uncertain cases.
5

How the plan comes together

disposition · handover

medically fit

Observation period complete per TOXBASE, levels safe, ECG and obs normal.

Then: mental-health assessment before discharge for any intentional overdose.

admit / escalate

Ongoing toxicity, a treatment (e.g. NAC) running, cardiotoxicity, or a reduced GCS → admit; critical care if unstable.

Hand over: agent, dose, timing, levels, ECG, treatment given, and the TOXBASE plan.

🩺
Pearl

The two things that catch people out: a silent paracetamol overdose that only a level reveals, and a re-sedating opioid patient after the naloxone wears off. Guard against both. Nicely done getting here.

This is a sensitive topic. If you or someone you know is struggling, support is available — in an emergency contact your local emergency number, and in the UK you can call the Samaritans on 116 123.