naloxone

Adjunctive therapy • Brands: Narcan

Last reviewed: 2025-12-31

General information

Class: Adjunctive therapy
Common US brands: Narcan
Typical dose range: Intranasal naloxone devices are single use. Labeling for Narcan nasal spray recommends administering one spray into one nostril as quickly as possible when overdose is suspected (label).
Therapeutic drug monitoring not routinely recommended.
Last reviewed: 2025-12-31

Dosing & forms

Forms/strengths: Intranasal spray devices (e.g., Narcan 4 mg) (label).; Injectable naloxone products (label/clinical).
Typical range: Intranasal naloxone devices are single use. Labeling for Narcan nasal spray recommends administering one spray into one nostril as quickly as possible when overdose is suspected (label).

Mechanism (brief)

Opioid receptor antagonist used for the emergency treatment of known or suspected opioid overdose (respiratory and/or CNS depression). Because naloxone’s duration is often shorter than the opioid involved, repeat dosing and emergency medical evaluation are commonly required (label/guideline).

Metabolism & Half‑life

Metabolism: Hepatic glucuronidation to naloxone-3-glucuronide (label)
Half‑life: Single-dose range 0.5–2.1 h

Therapeutic Drug Monitoring (TDM)

Recommended: No

View labelExact

Monitoring highlights

After administration, continued surveillance is essential because recurrent respiratory depression can occur; labeling emphasizes repeat dosing when needed while emergency services are activated (label).
Monitor for withdrawal-related agitation and vomiting with attention to airway/aspiration safety (label/clinical).
When naloxone is co-prescribed, clinicians often review overdose recognition, device use, storage, and expiration tracking with patients and close contacts (clinical).

Sources

NARCAN (naloxone hydrochloride) nasal spray prescribing information — DailyMed (2025)
Naloxone hydrochloride injection prescribing information — DailyMed (2024)
Are take-home naloxone programmes effective? Systematic review utilizing application of the Bradford Hill criteria — Addiction (2016)
TIP 63: Medications for Opioid Use Disorder — SAMHSA (2021)

General information

Class: Adjunctive therapy

Common US brands: Narcan

Typical dose range: Intranasal naloxone devices are single use. Labeling for Narcan nasal spray recommends administering one spray into one nostril as quickly as possible when overdose is suspected (label).

Therapeutic drug monitoring not routinely recommended.

Last reviewed: 2025-12-31

Dosing & forms

Forms/strengths: Intranasal spray devices (e.g., Narcan 4 mg) (label).; Injectable naloxone products (label/clinical).

Typical range: Intranasal naloxone devices are single use. Labeling for Narcan nasal spray recommends administering one spray into one nostril as quickly as possible when overdose is suspected (label).

Monitoring highlights

After administration, continued surveillance is essential because recurrent respiratory depression can occur; labeling emphasizes repeat dosing when needed while emergency services are activated (label).

Monitor for withdrawal-related agitation and vomiting with attention to airway/aspiration safety (label/clinical).

When naloxone is co-prescribed, clinicians often review overdose recognition, device use, storage, and expiration tracking with patients and close contacts (clinical).