Home › Compound Library › Naloxone Nasal (Narcan)

Naloxone Nasal (Narcan)

Opioidinhalation · inferred

Pure opioid receptor antagonist delivered as a 4 mg intranasal spray (now 8 mg Kloxxado also available) for emergency reversal of opioid overdose. Onset within 2-3 minutes; duration 30-90 minutes (may be shorter than the overdosing opioid so repeat dosing or EMS transport essential). Intranasal bioavailability ~47%. Available OTC in the US since 2023.

Projected serum levels — 4 mg, custom (shown daily)

Naloxone Nasal (Narcan)
Naloxone Nasal (Narcan) modeled serum levels, 4 mg custom (shown daily) over 15 days Population-based pharmacokinetic estimate. Steady state reached after approximately 1 days. 0 0.50 1 1.5 2 Day 0 Day 4 Day 8 Day 11 Day 15 Time on a regular schedule ≈ steady state · day 1

Maintenance schedule: 4 mg custom (shown daily) (inhalation).

Modeled steady state after ~1 days: peak ≈ 1.5 mg, trough ≈ 0.000 mg body load. Population-based estimate over 15 days for a 4 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Opioid
Route modeled
Inhalation
Model confidence
inferred
Half-life
2 h
Common dose
4 mg
Suggested maximum
8 mg/day
Reference dose range
2–8 mg (single dose)
Suggested cadence
custom (shown daily)
Validated against
4 mg inhalation — Cmax 0.005 mg/L at 0.50 h

Documented interactions

  • danger
    CBD (Cannabidiol) + Naloxone Nasal (Narcan) CYP inhibition

    CBD (Cannabidiol) reversible_inhibitor of UGT2B7 predicted to change Naloxone Nasal (Narcan) AUC by ~2.58x

  • danger
    Naltrexone (ReVia / Low-Dose LDN) + Naloxone Nasal (Narcan) Stacked effects

    Naloxone Nasal (Narcan) and Naltrexone (ReVia / Low-Dose LDN) both push the delta opioid, kappa opioid, and mu opioid in the same direction.

  • moderate
    Buprenorphine (Suboxone, Subutex) + Naloxone Nasal (Narcan) Stacked effects

    Buprenorphine (Suboxone, Subutex) and Naloxone Nasal (Narcan) both push the delta opioid and kappa opioid in the same direction.

  • moderate
    Carbamazepine (Tegretol) + Naloxone Nasal (Narcan) CYP induction

    Carbamazepine (Tegretol) inducer of CYP3A4 predicted to change Naloxone Nasal (Narcan) AUC by ~0.67x

  • moderate
    Contrave (Naltrexone/Bupropion) + Naloxone Nasal (Narcan) Stacked effects

    Contrave (Naltrexone/Bupropion) and Naloxone Nasal (Narcan) both push the kappa opioid and mu opioid in the same direction.

  • moderate
    Efavirenz (Sustiva) + Naloxone Nasal (Narcan) CYP induction

    Efavirenz (Sustiva) inducer of CYP3A4 predicted to change Naloxone Nasal (Narcan) AUC by ~0.53x

Serum checks 22 modeled interaction pairings for naloxone nasal (narcan) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. Pharmacokinetic properties and bioavailability of naloxone hydrochloride nasal spray in healthy adult subjects in comparison with intramuscular and intravenous routes Krieter P et al. · Journal of Clinical Pharmacology, 2016 DOI

    Pivotal PK study establishing intranasal naloxone 4 mg bioavailability (~47%) and peak concentrations comparable to 0.4 mg IM, supporting approval.

  2. Intranasal naloxone for treatment of opioid overdose Kim HK, Nelson LS · American Journal of Health-System Pharmacy, 2015 DOI

    Clinical review summarizing intranasal naloxone pharmacology, dosing, and its role in community opioid overdose reversal.

2 published studies referenced in the app, each with a plain-language summary.