US FDA approves nalmefene nasal spray, a fast-onset and long-duration opioid overdose reversal agent
The US Food and Drug Administration (FDA) has approved prescription nalmefene, an opioid receptor antagonist, for the emergency treatment of known or suspected opioid overdose.
If administered quickly, nalmefene can reverse or prevent the effects of opioid overdose, including respiratory depression, sedation and hypotension. Nalmefene has a longer duration of action than naloxone (the only other FDA-approved opioid overdose reversal drug) at fully reversing doses and has no opioid agonist activity.
Opioid overdose remains a major public health issue globally, and particularly in the US. Data from the CDC’s National Center for Health Statistics indicate that reported overdose deaths involving opioids in the US increased from 72,081 in the 12-month period ending February 2021 to 79,644 in the 12 months ending February 2023.
The approval of nalmefene nasal spray comes a couple of months after the FDA approved the first naloxone nasal spray for nonprescription use. Together, these approvals represent another vital step in ongoing efforts to prevent opioid-driven deaths.
Summary
Definition
History and exam
Key diagnostic factors
- history of opioid use disorder and dependence
- miosis
- bradypnea
- altered mental status
- dramatic response to naloxone
Other diagnostic factors
- fresh needle marks
- drug paraphernalia nearby
- decreased gastrointestinal motility
- old track marks on arms and legs
- pulmonary rales
- frothy pink sputum
- seizures
- dysrhythmias
Risk factors
- opioid use disorder and dependence
- recent abstinence in chronic users
- chronic pain
Diagnostic investigations
1st investigations to order
- therapeutic trial of naloxone
- Electrocardiogram (ECG)
Investigations to consider
- chest x-ray
- abdominal x-ray
- abdominal CT scan
- opioid urine screen
- gas chromatography/ mass spectrometry
Treatment algorithm
patients with signs of opioid overdose or toxicity: in cardiac arrest
patients with signs of opioid overdose or toxicity: not in cardiac arrest
Contributors
Authors
Ruben Thanacoody, MD, FRCP
Consultant Physician and Clinical Toxicologist
Director, National Poisons Information Service (Newcastle)
Newcastle-upon-Tyne
UK
Disclosures
RT declares that he has no competing interests.
Acknowledgements
Dr Ruben Thanacoody would like to gratefully acknowledge Dr Dean Olsen, a previous contributor to this topic.
Disclosures
DO declares that he has no competing interests.
Peer reviewers
William Winter, MD
Staff
Gynecologic Oncologist
Northwest Cancer Specialists
Rose Quarter Cancer Center
Portland
OR
Disclosures
WW 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.
Andrew Stolbach, MD
Assistant Professor
Johns Hopkins University
Baltimore
MD
Disclosures
AS declares that he has no competing interests.
Differentials
- Gammahydroxybutyrate (GHB)/gammabutyrolactone (GBL) overdose
- Clonidine/imidazolines overdose
- Antipsychotic overdose
More DifferentialsGuidelines
- Clinical practice guideline for prescribing opioids for pain
- 2021 resuscitation guidelines
More GuidelinesLog in or subscribe to access all of BMJ Best Practice
Use of this content is subject to our disclaimer