What happens during an opioid overdose and how can naloxone reverse it?

  • Opioids slow down the central nervous system, which slows down breathing and heart rate. An opioid overdose occurs when the brain can no longer regulate breathing, causing respiratory depression (not breathing enough) until breathing stops completely. Opioids, such as heroin, prescription opioids or fentanyl, bind to opioid receptors in the brain. Naloxone binds to the same receptors but are a “better fit,” so they essentially “kick” the opioids off and block the opioid receptors for about an hour.

Fentanyl

  • Fentanyl is a powerful synthetic (manufactured) opioid prescribed by physicians to treat patients with severe pain, such as post-surgical or cancer pain. Legally prescribed fentanyl generally comes in the form of a patch, nasal spray, lozenge, injection, tablets or films. However, illegally manufactured fentanyl can be found in a powdered form and is frequently used to “cut” heroin or in counterfeit prescription pills (including fake opioids and benzodiazepines).
  • Fentanyl is 50-100 times more potent than morphine and is often added to drugs without the user’s knowledge. This places users at a higher risk for overdose since a dose that appears safe may actually be lethal. Most users try to actively avoid fentanyl but are often unable to detect its presence.
  • The onset of an overdose caused by fentanyl can occur at a much quicker rate (sometimes within seconds) than heroin and may take multiple doses of naloxone to counteract due to the potency of fentanyl.  In the majority of cases, fentanyl overdoses appear very similar to other opioid overdoses. However, atypical overdose symptoms due to fentanyl have been reported, including:
    • Immediate blue or grey lips
    • Body stiffening/seizure like activity
    • Foaming at the mouth
    • Confusion before becoming unresponsive
  • Fentanyl overdoses are often indistinguishable from overdoses caused by any other opioids and should be responded to similarly beginning with administering naloxone, calling 911, and starting rescue breaths (see above).
Categories FAQ

What are the risks associated with naloxone use?

  • Minimal risks are associated with naloxone. Naloxone cannot get you “high” and is not addictive. Someone who is physically dependent on opioids may experience some withdrawal symptoms (such as nausea, vomiting, sweating, aches, or irritability).

How long does naloxone last?

  • The effects of naloxone only stay in the system for about an hour, which is a shorter amount of time than some opioids. This means that it is possible to slip back into an overdose after the naloxone wears off. It is important to always call 911 in the case of an overdose, even if naloxone is administered

*Missouri has recently enacted a 911 Good Samaritan Law that offers protection to those who call 911 during an overdose. Click here for more information.

Can you overdose on naloxone?

  • No, you cannot overdose on naloxone. If a person experiencing an opioid overdose does not respond to the first dose of naloxone in 2-3 minutes, it is safe to administer additional doses.

What types of naloxone are available?

  • Intramuscular:
    • A naloxone injection directly into the muscle of the upper thigh or upper arm.
  • Auto injector – Evizio:
    • A ready-to-use, automatic injection device, which gives electronic voice-guided, step-by-step instructions. Note, this version is typically very expensive (around $4000) and may not be covered by some insurances.
  • Prepackaged Nasal Spray – Narcan Nasal Spray:
    • A preassembled, ready-to-use device. After the nasal spray nozzle is gently inserted into the person’s nostril, firmly press the plunger to spray one entire dose into one nostril. The naloxone is absorbed into the bloodstream so there is no need for the person to inhale it for the medication to work.
  • Nasal Atomizer:
    • A pre-filled cartridge of naloxone and a nasal atomizer that requires assembly. Note, this device is not FDA approved.

Naloxone can also be administered intravenously (through an IV) by medical professionals.

Naloxone, Narcan, Naltrexone, Suboxone… What’s the difference?

  • Naloxone is the generic name for the opioid overdose reversal (“antidote”) medication.
  • Narcan is one brand name of the prepackaged nasal spray naloxone
  • Suboxone is the brand name for buprenorphine + naloxone (prescribed as Medication Assisted Treatment for opioid use disorder)
  • Naloxone ≠ naltrexone (longer-acting opioid antagonist for alcohol use disorder treatment and relapse prevention in opioid use disorder)