What is Narcan?
Narcan™ (generic name naloxone) is an opiate antidote. Opiates include heroin as well as prescription opiates like morphine, codeine, OxyContin, methadone and Vicodin. Narcan is a prescription medicine that blocks the effects of opiates. It cannot be abused or used to get a person high. If given to a person who has not taken opiates it will not have any effect on them. (a)
Naloxone hydrochloride prevents or reverses the effects of opioids, including respiratory depression, sedation, and hypotension. Also, it can reverse the psychotomimetic and dysphoric effects of agonist-antagonist such as pentazocine.
Naloxone hydrochloride is an essentially pure narcotic antagonist, i.e., it does not possess the “agonistic” or morphine-like properties characteristic of other narcotic antagonists; Naloxone does not produce respiratory depression, psychotomimetic effects or pupillary constriction. In the absence of narcotics or agonistic effects of other narcotic antagonists it exhibits essentially no pharmacologic activity.
Naloxone has not been shown to produce tolerance nor to cause physical or psychological dependence. (b)
How does Narcan work?
If a person has taken opiates and is then given Narcan, the opiates will be knocked off the opiate receptors in the brain. This reverses the effects of an opiate overdose including restoring breathing that has stopped or slowed down. Death typically does not occur until several hours after an opiate overdose, which provides a window of opportunity to intervene by calling 911, giving rescue breathing and administering Narcan. Narcan can help even if opiates are taken with alcohol or other drugs.
Narcan can be given by injection (into veins or muscles) or with a nasal spray device (into the nose). It generally works within about 5 minutes. Narcan starts to wear off after about 30 minutes and is mostly gone after about 90 minutes. By this time the body has metabolized enough of the opiates that the user is unlikely to stop breathing again. However, in some cases – such as after taking a massive dose or long-acting opiates like methadone – the patient might need another dose and longer medical observation. (a)
For more information on Clinical Services of Rhode Island’s Narcan training program: