Nalmefene is the first medication approved for alcoholism with the primary goal of reducing alcohol intake in an as needed approach. Nalmefene received a marketing authorization valid throughout the European Union on February 25, 2013 and is under development in Asia. Nalmefene is an opioid system modulator with a distinct μ, δ, and κ receptor profile. In vitro studies have demonstrated that Nalmefene is a selective opioid receptor ligand with antagonist activity at the μ and δ receptors and partial agonist activity at the κ receptor. In vivo studies have demonstrated that nalmefene reduces alcohol consumption, possibly by modulating cortico-mesolimbic functions. In the US, immediate-release injectable nalmefene was approved in 1995 as an antidote for opioid overdose. It was sold under the trade name Revex. The product was discontinued by its manufacturer around 2008. Currently Nalmefene is sold under the trade name Selincro. Selincro is indicated for the reduction of alcohol consumption in adult patients with alcohol dependence who have a high drinking-risk level, without physical withdrawal symptoms and who do not require immediate detoxification.