Comparative Pharmacology
Head-to-head clinical analysis: NARCAN versus REVIA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NARCAN versus REVIA.
NARCAN vs REVIA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Opioid receptor antagonist; binds competitively to mu, kappa, and delta opioid receptors, reversing opioid 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.
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.
50 mg orally once daily
None Documented
None Documented
Approximately 1 hour in adults; context: shorter than most opioids (e.g., morphine 2-4 h), necessitating repeated doses for prolonged opioid effects.
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.
Primarily hepatic metabolism (glucuronidation) followed by renal excretion of metabolites; <5% excreted unchanged in urine.
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