Opioids and Naloxone

Adapted with permission of Ottawa Public Health. For educational and non-commercial purposes only.

What is fentanyl?

Fentanyl is an opioid that is much more toxic than most other opioids (like heroin, morphine, fentanyl, methadone and codeine). Fentanyl is usually prescribed in a patch form as a painkiller. It is around 50 to 100 times more toxic than morphine. This makes the risk of accidental overdose much higher.

There are also different fentanyls being made illegally and sold on the streets. This illicit fentanyl is often made as a powder and mixed with other drugs (like heroin, cocaine or crack). It is also being pressed into pills made to look like other prescription pills (like oxycontin, eighties or percocet) or other pills including speed. It may be in drugs that are in powder, liquid or pill form.

What is carfentanil?

Carfentanil is an opioid that is used by veterinarians for very large animals like elephants. It is not for human use. It is approximately 100 times more toxic than fentanyl and 10,000 times more toxic than morphine. This means carfentanil can be deadly in extremely small amounts.

There is no easy way to know if carfentanil is in your drugs, you can’t see it, smell it or taste it.

What is naloxone?

Naloxone is a medication that can temporarily reverse the effects of an opioid overdose. Opioids include drugs like heroin, morphine, fentanyl, methadone and codeine.

How does Naloxone work?

In an opioid overdose a person’s breathing slows down or stops. Naloxone blocks the effect of opioids on the brain. It temporarily reverses these effects on a person’s breathing. Giving naloxone can prevent death or brain damage from lack of oxygen. Naloxone usually starts working in 1 to 5 minutes and the effects of naloxone only last for 30 to 60 minutes. 

If the opioid is still in the body after the naloxone wears off, the overdose can return so repeated doses may be needed.

Who can take naloxone?

Naloxone is a very safe drug which is used across ages. It is safe for someone pregnant or lactating, and also if they have medical conditions such as heart, respiratory, liver or kidney disease.

The only reason to NOT give naloxone would be if there was history of allergy to naloxone or its ingredients - which you likely wouldn’t know. 

Learn more about naloxone from the following University of Waterloo video: