Naloxone
Naloxone hydrochloride
Brand names:Narcan, Evzio, Kloxxado
A competitive mu-opioid receptor antagonist that reverses opioid-induced respiratory depression. Naloxone is carried at every level of EMS and is a required medication on PA ALS, IALS, and BLS vehicles. The drug is also positioned as a TEMS and TCCC safety countermeasure for accidental or operationally-induced opioid exposure.
Pharmacology and Actions
Naloxone competitively binds and displaces opioid agonists from mu, kappa, and delta opioid receptors. The result is rapid reversal of opioid effects: respiratory depression, sedation, and miosis. Naloxone has no agonist activity of its own; in patients without opioid on board, the drug produces minimal clinical effect. Duration of action (30 to 90 minutes) is shorter than many opioids, which means re-narcotization (return of opioid effects after naloxone wears off) is a critical concern, particularly with fentanyl analogues.
Indications
- Suspected opioid overdose with respiratory depression (RR less than 12 with altered mental status)
- Reversal of opioid-induced respiratory depression in any clinical setting
- Operational exposure to fentanyl analogues during tactical operations or evidence handling
- Reversal of opioid sedation for diagnostic purposes when other causes of altered mental status are being evaluated
- Pediatric opioid overdose
Absolute Contraindications
- Known naloxone allergy (rare)
- Cardiac arrest in the absence of suspected opioid involvement should not delay standard ACLS
Precautions and Side Effects
Precipitated opioid withdrawal in opioid-dependent patients can produce severe agitation, violent behavior, vomiting, diarrhea, sweating, and rarely pulmonary edema. The goal of naloxone administration is restoration of adequate ventilation, not full reversal of all opioid effects. Titrate dosing to respiratory adequacy, not to consciousness. Naloxone has a shorter duration than most opioids; monitor for re-narcotization for at least 60 to 90 minutes after the last dose. Fentanyl and its analogues may require higher or repeated doses to maintain reversal.
Adult Dosing
Pediatric Dosing
Pediatric dosing per PA Protocol 7002P Pediatric Dose Chart: 0.1 mg/kg IM/IN/IV/IO, maximum 2 mg per dose. May repeat every 2 to 4 minutes. Pediatric naloxone is generally available without medical command order for suspected opioid overdose with respiratory depression.
Pharmacokinetics
Peak Effect: IV: 2 to 5 minutes. IM: 5 to 15 minutes. IN: 5 to 10 minutes.
Duration: 30 to 90 minutes (often shorter than the opioid being reversed)
Storage and Handling
Store at controlled room temperature (15 to 30 degrees Celsius). Protect from light. Nasal spray devices, prefilled syringes, and auto-injectors have specific storage requirements per manufacturer. Most formulations are stable in standard EMS bag environments.
Reconstitution:
Naloxone is supplied as a sterile solution in concentrations of 0.4 mg/mL and 1 mg/mL injection, 4 mg nasal spray, and auto-injector forms. No reconstitution required.
TCCC and TECC Role
Naloxone is positioned in TCCC and TEMS contexts primarily as a safety countermeasure for inadvertent opioid exposure during tactical operations, including fentanyl analogue exposure during evidence handling, clandestine lab response, and operational events where weaponized opioids are a concern. The drug is also carried for reversal of TCCC-administered opioid analgesia (fentanyl, OTFC) if respiratory depression develops. The 2026 guidelines emphasize having naloxone ready any time an opioid is administered.
Naloxone is the drug that saves lives at every level of prehospital care. The IN route through a mucosal atomizer device transformed lay-rescuer overdose response; civilian opioid overdose deaths would be significantly higher without widespread naloxone distribution. In tactical contexts, naloxone is the safety net that makes fentanyl analgesia viable. Always have naloxone drawn up and immediately accessible whenever opioids are administered. Remember the duration mismatch: a single dose of naloxone may wear off before the opioid does, particularly with fentanyl. Re-dose as needed and continue monitoring.
Giving the full 2 mg or 4 mg dose to a known chronic opioid user and producing severe precipitated withdrawal. The goal is restoration of adequate respiratory drive, not waking the patient up. Titrate in 0.04 to 0.1 mg increments IV when possible, and target spontaneous respirations greater than 12 per minute with adequate oxygen saturation. The patient who is breathing and responsive to pain but not fully alert is a better outcome than a violent withdrawal patient.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
If this content is being viewed during a medical emergency, call 911 immediately and follow the direction of your local emergency dispatch and medical control. Do not use this reference as a substitute for emergency medical services.
Drug information evolves. Last reviewed dates and source citations are provided for each entry. Confirm currency against the cited source before clinical use.
Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Naloxone
| IV/IO | Standard EMS: 0.4 to 2 mg IV/IO, titrated to respiratory effort. PA Protocol 7002A pediatric/adult: 0.1 mg/kg IV/IO, maximum initial dose 0.4 mg, with repeat dosing 0.1 mg/kg (max 2 mg) every 2 to 4 minutes as needed. For known chronic opioid users, consider lower titrated doses to avoid withdrawal. (1 to 2 minutes) |
| IM | 0.4 to 2 mg IM when IV access is unavailable. Onset is slower but more sustained than IN. (2 to 5 minutes) |
| IN | Narcan nasal spray: 4 mg (one prefilled device) intranasally. May repeat every 2 to 3 minutes as needed. Kloxxado: 8 mg intranasally for higher-potency opioid overdoses. (2 to 5 minutes) |