See the DrugPatentWatch profile for narcan
How fast does Narcan (naloxone) work for an opioid overdose?
Narcan (naloxone) can start reversing the effects of an opioid overdose within minutes. If it is going to work, it typically takes effect within about 2 to 5 minutes, especially by restoring breathing. Many people will show improved alertness and breathing soon after dosing, but response times can vary by the opioid involved and how much was taken.
What should you look for after giving naloxone?
The most important sign is breathing. After naloxone, someone may start to breathe more normally or at a higher rate, become more responsive, or have improved skin color. If there is little to no change soon after dosing, the overdose may still be ongoing.
What happens if there’s no improvement after the first dose?
Opioids can last longer than naloxone, so symptoms can return after the first dose. If the person does not improve, or breathing slows again, additional doses of naloxone may be needed. Follow the instructions on the specific Narcan product label and any local emergency guidance, and call emergency services right away.
How does Narcan’s timing differ by opioid or situation?
Narcan works by displacing opioids from their receptors, so the speed of reversal depends on what opioid is involved and how much has been taken. Overdoses involving longer-acting opioids or very large amounts can require repeated dosing, and improvement may not be immediate if breathing is already severely compromised.
How quickly should you call for help?
Even if naloxone is given, overdose is a medical emergency. Emergency services should be contacted immediately when an overdose is suspected, because the person may still need monitoring and additional interventions.