Overdose and Toxidromes
Objective: Sort an overdose into a toxidrome, a pattern of drug effects. Protect the airway first. Use only the antidote your protocol allows.
Why this matters
People often take more than one drug. Bottles can be wrong, and the patient may not give a history. A toxidrome is a pattern of drug effects. Use that pattern to choose airway care and the antidote your protocol allows. You are not doing a hospital toxicology workup in the ambulance.
- First, open the airway and ventilate if breathing is slow. Naloxone is for breathing. Do not use it as a goal to wake the patient all the way up.
- You will not get a full toxicology screen. Bring the bottles, the patches, and the bystander’s story.
- A patient who is hot, agitated, and hyperthermic needs cooling, and a benzodiazepine if your protocol allows it. Do not leave them to ride it out. Make the scene safe before you go in.
High-Yield Patterns
- Opioid. Slow breathing and depressed mentation. Pupils may be pinpoint, but mixed drugs change that. Give naloxone to restore breathing, not necessarily full wakefulness.
- Sympathomimetic, such as cocaine or methamphetamine. Agitation, fast heart rate, high blood pressure, heat, and sweat. Cool them and use a benzodiazepine per protocol. Look for trauma and acute coronary syndrome.
- Anticholinergic. Delirium, hot dry skin, dilated pupils, and urinary retention. Care is supportive. Use a specific antidote only if your protocol allows it.
- Cholinergic, such as an organophosphate. Teaching lists include SLUDGE and DUMBELS. The findings you use are wet secretions, small pupils, a slow heart rate, diarrhea, and tearing. Make the scene safe first. Give atropine or pralidoxime only in a hazmat system or when your protocol says so.
- Sedative-hypnotic. Altered mental status with vital signs that are relatively preserved early. Support the airway.
Clinical sequence
- Make the scene safe and follow your protective-equipment rules. Do not invent a fentanyl-powder response that is not in your policy.
- If they are breathing too slowly, open the airway and ventilate first.
- Check glucose in any altered patient.
- Get a 12-lead when there is chest pain or a sympathomimetic stress picture.
- Give antidotes only as authorized. Bring bottles and packets to the emergency department.
- Do not make them vomit. Field decontamination is limited.
Key points
- Treat what you see. Do not treat the drug name alone.
- Slow breathing kills more opioid patients than a low saturation number by itself.
- For severe agitation, follow your restraint and sedation protocol. Say “severe agitation.” Do not use the outdated label “excited delirium.”
Common errors
- Do not give a large naloxone dose that causes violent withdrawal when your protocol allows a smaller titration.
- Do not miss trauma because the patient is intoxicated.
- Do not enter an unsafe chemical scene without training.
- Do not reach for flumazenil in an undifferentiated sedative overdose. It is not naloxone, and it can cause seizures. Support the airway unless a specific protocol says otherwise.
- Airway and ventilation come first if breathing is slow.
- The pattern is opioid, sympathomimetic, anticholinergic, or cholinergic.
- Check glucose in an altered patient. Give antidotes only when you are authorized.
- Bring the bottles. Do not make them vomit.
Practice
One-minute check
Your partner gives three overdose scenes. Name the toxidrome and the first move for each: airway support, cool and calm, or supportive care. Treat what you see. Do not treat the bottle label alone.
Then write 8–10 lines on a fictional call in Narrative Coach (never real PHI).
Sources & Further Study
Named guidelines for further study. They are not clinical orders and do not replace your protocol or medical direction.
- America’s Poison Centers / poison control (1-800-222-1222)
- AHA 2025 Part 10: Special Circumstances — suspected opioid respiratory arrest: support ventilation and give naloxone; see the naloxone lesson
- NASEMSO National Model EMS Clinical Guidelines (2022)
- Treat the toxidrome and the airway first. Give antidotes only when you are authorized.
- Follow your overdose, naloxone, and hazmat protocols.
Education only. Apply learning within your protocols and medical direction. This is not clinical care guidance.
Check Your Understanding
Questions drawn only from this lesson. After you check, the key is highlighted. Education practice — not a certification exam.