Comparative Pharmacology
Head-to-head clinical analysis: NALMEFENE HYDROCHLORIDE versus NALTREXONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NALMEFENE HYDROCHLORIDE versus NALTREXONE.
NALMEFENE HYDROCHLORIDE vs NALTREXONE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Nalmefene is an opioid receptor antagonist with high affinity for mu, kappa, and delta receptors, and partial agonist activity at kappa receptors.
Naltrexone is a pure opioid antagonist that competitively binds to μ-opioid receptors, blocking the effects of endogenous and exogenous opioids. It also antagonizes κ- and δ-opioid receptors to a lesser extent.
18 mcg intranasally once, repeated after 2-3 minutes if needed; maximum 2 doses (36 mcg) per episode. Alternatively, 0.5 mg subcutaneously or intramuscularly once, repeated after 2-3 minutes if needed; maximum 1.5 mg per episode.
Oral: 50 mg once daily for opioid dependence; 25 mg initially for first dose to minimize adverse effects. Intramuscular: 380 mg every 4 weeks for alcohol dependence.
None Documented
None Documented
Clinical Note
moderateMethylnaltrexone + Fesoterodine
"The serum concentration of the active metabolites of Fesoterodine can be increased when Fesoterodine is used in combination with Methylnaltrexone."
Clinical Note
moderateNaltrexone + Methadone
"The therapeutic efficacy of Methadone can be decreased when used in combination with Naltrexone."
Clinical Note
moderateNaltrexone + Dabigatran etexilate
"The serum concentration of the active metabolites of Dabigatran etexilate can be increased when Dabigatran etexilate is used in combination with Naltrexone."
Clinical Note
moderateTerminal elimination half-life: ~10.8 hours (range 8–13 hours); clinically supports twice-daily dosing or use in alcohol use disorder
Naltrexone: 3.9–10.3 hours; active metabolite 6β-naltrexol: 12.9 hours. Context: Trough levels of 6β-naltrexol sustain receptor blockade for 24–48 h.
Primarily renal (approximately 50% unchanged drug); biliary/fecal excretion accounts for ~20%
Primarily renal (60% as metabolites, including 6β-naltrexol; <2% unchanged) and biliary/fecal (30%).
Category C
Category A/B
Opioid Antagonist
Opioid Antagonist
Naltrexone + Sufentanil
"The therapeutic efficacy of Sufentanil can be decreased when used in combination with Naltrexone."