"Naloxone is the most common antidote used for overdoses. It is normally ambulance personnel who administer naloxone in connection with opioid overdoses, and doses are administered by intramuscular or intravenous injection. It is now being discussed whether naloxone in the form of a mouth spray should be available to others as well, as first aid for someone who has overdosed
until the ambulance arrives."
Norwegian Institute for Alcohol and Drug Research, "The Drug Situation in Norway 2012: annual report to the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA)," (Oslo, Norway: December 2012), p. 38.