Comparative Pharmacology
Head-to-head clinical analysis: EVZIO AUTOINJECTOR versus NARCAN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EVZIO AUTOINJECTOR versus NARCAN.
EVZIO (AUTOINJECTOR) vs NARCAN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Competitive antagonist at mu-opioid receptors, reversing opioid-induced respiratory depression and other central nervous system depressant effects.
Opioid receptor antagonist; binds competitively to mu, kappa, and delta opioid receptors, reversing opioid effects.
Adults: 2 mg intramuscularly or subcutaneously into the anterolateral thigh, repeat every 2-3 minutes as needed until emergency medical assistance arrives.
Initial dose: 0.4 mg to 2 mg IV, IM, or SC, repeated every 2 to 3 minutes as needed. For opioid-induced respiratory depression, may use 0.1 to 0.2 mg IV increments in patients with opioid dependence to avoid withdrawal.
None Documented
None Documented
Terminal elimination half-life of naloxone is approximately 1–2 hours in adults. The short half-life results in a duration of action that may be shorter than that of the opioid (e.g., fentanyl, methadone), necessitating repeated doses or continuous infusion. In neonates, half-life is prolonged (3–4 hours).
Approximately 1 hour in adults; context: shorter than most opioids (e.g., morphine 2-4 h), necessitating repeated doses for prolonged opioid effects.
Naloxone is primarily metabolized in the liver via glucuronidation, with minor contributions from N-dealkylation. The metabolites (naloxone-3-glucuronide) and parent drug are excreted renally. Approximately 50% of a dose is excreted in urine as naloxone-3-glucuronide, 25% as unchanged naloxone (after IV), and <5% in feces. Biliary excretion is minimal (<1%).
Primarily hepatic metabolism (glucuronidation) followed by renal excretion of metabolites; <5% excreted unchanged in urine.
Category C
Category C
Opioid Antagonist
Opioid Antagonist