Comparative Pharmacology
Head-to-head clinical analysis: EVZIO AUTOINJECTOR versus REVIA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EVZIO AUTOINJECTOR versus REVIA.
EVZIO (AUTOINJECTOR) vs REVIA
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.
Naltrexone is a mu-opioid receptor antagonist that competitively binds to opioid receptors, blocking the effects of endogenous and exogenous opioids. It also exhibits some antagonistic activity at kappa and delta opioid receptors.
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
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 half-life of naltrexone is approximately 4 hours; its active metabolite, 6β-naltrexol, has a half-life of about 13 hours. Clinically, the prolonged blockade of opioid receptors (up to 72 hours after a single oral dose) is attributed to the metabolite's accumulation and high receptor affinity.
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 and glucuronide conjugates; fecal: minor; approximately 60% of a dose is excreted in urine within 48 hours (with about 20% as unchanged naltrexone and the rest as metabolites, mainly 6β-naltrexol).
Category C
Category C
Opioid Antagonist
Opioid Antagonist