Nalmefene hydrochlorideProduct ingredient for Nalmefene

Nalmefene, a 6-methylene analogue of naltrexone, is an opioid receptor antagonist.⁸ It acts as an antagonist at the mu (μ)-opioid and delta (δ)-opioid receptors and a partial agonist at the kappa (κ)-opioid receptor.⁷

In Europe, nalmefene oral tablets are used to reduce alcohol consumption in adults with alcohol dependence.⁷ Nalmefene was approved in the United States in 1995 as an antidote for opioid overdose.⁴ Nalmefene injection is used to manage known or suspected opioid overdose. It is used for complete or partial reversal of opioid drug effects, including respiratory depression, induced by either natural or synthetic opioids.⁸ The nasal spray formulation of nalmefene was approved by the FDA in May 2023.¹¹