Comparative Pharmacology
Head-to-head clinical analysis: EVZIO AUTOINJECTOR versus NALTREXONE HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EVZIO AUTOINJECTOR versus NALTREXONE HYDROCHLORIDE.
EVZIO (AUTOINJECTOR) vs NALTREXONE HYDROCHLORIDE
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.
Competitive antagonist at mu, kappa, and delta opioid receptors, with highest affinity for mu receptors. Also acts as an antagonist at the toll-like receptor 4 (TLR4).
Adults: 2 mg intramuscularly or subcutaneously into the anterolateral thigh, repeat every 2-3 minutes as needed until emergency medical assistance arrives.
50 mg orally once daily for opioid dependence; 25 mg orally once daily for alcohol dependence, may increase to 50 mg after one week.
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).
Terminal elimination half-life: ~4 hours for naltrexone; its major active metabolite, 6-β-naltrexol, has a half-life of ~13 hours. The longer half-life of the metabolite contributes to sustained receptor blockade.
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%).
Renal: primarily as unchanged drug (<2%) and metabolites (mainly 6-β-naltrexol, glucuronide conjugates); approximately 60% of dose excreted in urine (including metabolites) and about 30% in feces via biliary excretion.
Category C
Category A/B
Opioid Antagonist
Opioid Antagonist