Opioid overdose

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Last reviewed: 12 Sep 2025

Last updated: 09 Jul 2025

Opioid overdose occurs when a person takes opioids in larger quantities than are physically tolerated.

Signs include central nervous system and respiratory depression, miosis, and apnea.

The patient's history from bystanders/friends/family can assist diagnosis.

Initial treatment consists of ensuring adequate ventilation and consideration of the opioid antagonist naloxone.

Patients should be monitored for resedation and antidote dose repeated if necessary.

Definición

An opioid is any synthetic or natural agent that stimulates opioid receptors and produces opium-like effects. Opiates are opioids naturally derived from the opium poppy, Papaver somniferum, and include morphine and codeine. Synthetic opioids are substances synthesized in a laboratory that act on opioid receptors. Opioids are used in the treatment of pain but are often sold illicitly and misused for their euphoric effects. Misuse of synthetic opioids parallels that of heroin and prescription opioid analgesics.

An overdose occurs when larger quantities than physically tolerated are taken, resulting in central nervous system and respiratory depression, miosis, and apnea, which can be fatal if not treated rapidly.

Many illicitly produced synthetic opioids are more potent than morphine and heroin and thus have the potential to result in a fatal overdose.[1]

Anamnesis y examen

Principales factores de diagnóstico

history of opioid use disorder and dependence
miosis
bradypnea
altered mental status
dramatic response to naloxone

Todos los datos

Otros factores de diagnóstico

fresh needle marks
drug paraphernalia nearby
decreased gastrointestinal motility
old track marks on arms and legs
pulmonary rales
frothy pink sputum
seizures
dysrhythmias

Todos los datos

Factores de riesgo

history of prescribed opioids
opioid use disorder and dependence
recent abstinence in chronic users
taking opioids by injection

Todos los datos

Pruebas diagnósticas

Primeras pruebas diagnósticas para solicitar

therapeutic trial of naloxone
Electrocardiogram (ECG)

Todos los datos

Pruebas diagnósticas que deben considerarse

chest x-ray
abdominal CT scan
abdominal x-ray
opioid urine screen
gas chromatography/ mass spectrometry

Todos los datos

Algoritmo de tratamiento

Agudo

without retained drug packages

with retained drug packages

Colaboradores

Autores

Ruben Thanacoody, MD, FRCP, FRCP(Edin), FEAPCCT

Consultant Physician and Clinical Toxicologist

Director, National Poisons Information Service (Newcastle)

Honorary Clinical Senior Lecturer, Newcastle University

Newcastle-upon-Tyne

Divulgaciones

RT declares that he has no competing interests. RT is an author of a reference cited in this topic.

Agradecimientos

Dr Ruben Thanacoody would like to gratefully acknowledge Dr Dean Olsen, a previous contributor to this topic.

Divulgaciones

DO declares that he has no competing interests.

Revisores por pares

Joseph Donroe, null

Associate Professor of Medicine

Yale School of Medicine

New Haven

Divulgaciones

JD declares that he has no competing interests.

Anne-Maree Kelley, MD, MClinEd, FACEM

Director

Joseph Epstein Centre for Emergency Medicine Research

Western Health Sunshine Hospital

St Albans

Australia

Disclosures

AMK has received grant funding for research into intranasal delivery of naloxone in heroin overdose.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Dowell D, Ragan KR, Jones CM, et al. CDC clinical practice guideline for prescribing opioids for pain - United States, 2022. MMWR Recomm Rep. 2022 Nov 4;71(3):1-95.Full text Abstract

Dezfulian C, Orkin AM, Maron BA, et al. Opioid-associated out-of-hospital cardiac arrest: distinctive clinical features and implications for health care and public responses: a scientific statement from the American Heart Association. Circulation. 2021 Apr 20;143(16):e836-70.Full text Abstract

Resuscitation Council UK. 2021 resuscitation guidelines. 2021 [internet publication].Full text

Williams K, Lang ES, Panchal AR, et al. Evidence-based guidelines for EMS administration of naloxone. Prehosp Emerg Care. 2019 Nov-Dec;23(6):749-63.Full text Abstract

Lavonas EJ, Akpunonu PD, Arens AM, et al. 2023 American Heart Association focused update on the management of patients with cardiac arrest or life-threatening toxicity due to poisoning: an update to the American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2023 Oct 17;148(16):e149-84.Full text Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials
- Gammahydroxybutyrate (GHB)/gammabutyrolactone (GBL) overdose
- Clonidine/imidazolines overdose
- Antipsychotic overdose
More Differentials
Guidelines
- Joint RCEM and NPIS best practice guideline: assessment and management of acute opioid toxicity in adults in the emergency department
- 2023 American Heart Association focused update on the management of patients with cardiac arrest or life-threatening toxicity due to poisoning: an update to the American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care
More Guidelines
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Opioid overdose

Summary

Definición

Anamnesis y examen

Principales factores de diagnóstico

Otros factores de diagnóstico

Factores de riesgo

Pruebas diagnósticas

Primeras pruebas diagnósticas para solicitar

Pruebas diagnósticas que deben considerarse

Algoritmo de tratamiento

without retained drug packages

with retained drug packages

Colaboradores

Autores

Ruben Thanacoody, MD, FRCP, FRCP(Edin), FEAPCCT

Divulgaciones

Agradecimientos

Divulgaciones

Revisores por pares

Joseph Donroe, null

Divulgaciones

Anne-Maree Kelley, MD, MClinEd, FACEM

Disclosures

Peer reviewer acknowledgements

Disclosures

References

Key articles

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials

Guidelines

Log in or subscribe to access all of BMJ Best Practice

Log in or subscribe to access all of BMJ Best Practice

Log in to access all of BMJ Best Practice