sentences:  Intravenous doses of nalmefene have been shown effective at counteracting the respiratory depression produced by opioid overdose.When nalmefene is used to treat an opioid overdose, doses of nalmefene greater than 1.5 mg do not appear to give any greater benefit than doses of only 1.5 mg.
  
  Nalmefene is used in Europe to reduce alcohol dependence and NICE recommends the use of nalmefene to reduce alcohol consumption in combination with psychological support for people who drink heavily.Based on a meta analysis, the usefulness of nalmefene for alcohol dependence is unclear.