This medication is used for the emergency treatment of known or suspected opioid overdose. Serious overdose symptoms may include unusual sleepiness, unusual difficulty waking up, or breathing problems (ranging from slow/shallow breathing to no breathing). Other symptoms of overdose may include very small “pinpoint” pupils, slow heartbeat, or low blood pressure. If someone has serious overdose symptoms but you are not sure if he or she has overdosed, give this medication right away anyway, since lasting slow/shallow breathing may cause permanent damage to the brain or death.

This medication belongs to a class of drugs known as opioid antagonists.