What is Naloxone and it works?
Naloxone is a medication that reverses the effect of opioids. In an emergency overdose situation it can be a lifesaver.
The medication itself has been around for over 50 years, is on the World Health Organisation’s list of essential medicines and more recently was recommended in WHO guidelines for the community management of opioid overdose. The practice of putting naloxone in the hands of people most likely to witness an overdose (people who use drugs) began in the 90’s.
How it works
Naloxone works by temporarily displacing the opioids from the receptors in the brain to reverse the breathing difficulties being experienced by the person who has overdosed [^1]. When administered by intramuscular injection this only takes a few minutes although several doses may be required depending on the person’s response and the opioid involved.
It is a ‘competitive antagonist’ which means that it competes with opioids for the receptors and then blocks them temporarily. So it does not cause any kind of ‘high’ or intoxication, its only job is to reverse the effects of respiratory depression caused by opioids.
Opioids include methadone, codeine, tramadol, fentanyl and morphine amongst others, so it is not only for use in suspected heroin overdoses.
If the person who has overdosed is physically dependent on opioids they may experience acute withdrawal syndrome following naloxone administration, the risk of which increases with the amount of naloxone that has been administered.
Naloxone is very short-acting and the effects will begin to wear off after 20-30 minutes, after which the opioids will re-attach to the receptors. It is very important that the person does not use any further drugs while the naloxone is active as when it wears off they would likely overdose again.
Formulations
There are two forms of naloxone that anyone can use without medical training or authorization: prefilled nasal spray and injectable. The decision on which form of naloxone to use or carry can depend many factors such as cost, availability, and comfort level. Both are safe, effective, and can help save a life.
Additional Material
What is Naloxone?