When someone consumes too much cannabis they can experience unpleasant side effects such as anxiety, paranoia, nausea, and even hallucinations. Is this episode considered an overdose? Self-poisoning? Toxicity? Impairment? Or simply “greening” out?

As the nationwide legalization of recreational cannabis approaches, the public and medical professionals alike appear to be divided on the right language to use when describing a situation where someone has had too much.

Last week, a CTV News story based on the Canadian Institute for Health Information’s data on increased emergency room visits by patients overdosing on cannabis in Ontario received numerous responses from readers upset with the use of the word “overdose” in the context of marijuana.

Dr. Michael Verbora, the chief medical officer for the Toronto-based medical cannabis clinic Aleafia Total Health, said he suspects the strong reaction by some readers is because of the association between overdoses and the current opioid crisis plaguing the country.

“The moment you say the word ‘overdose’ the average image to the average person is going to be someone taking a substance that can cause a fatal reaction and they immediately assume that an overdose is fatal and that’s just because the biggest overdoses we see in society are with opiates,” he explained during a telephone interview with CTV News on Tuesday.

Verbora said the word overdose might technically be the correct label, but he thinks it should be avoided because of the negative connotations attached to it.

“If you break down the word ‘overdose’, the real definition is probably something around consuming too much of a product and then having adverse effects,” he said. “I just think a lot of people want to distance cannabis away from the opiate overdose crisis.”

Dr. Tony George, the chief of addictions division at The Centre for Addiction and Mental Health (CAMH), agrees that the associations with the term overdose imply something more serious.

“When I think of overdose I think of things that can potentially put your life at risk, like you stop breathing with opioids, and benzodiazepine and stimulants can cause fatal cardiac dysrhythmias that can kill you, but that’s not something that’s associated with cannabis,” he said.

Instead, George said cannabis users who may ingest too much of the drug can die in accidents if they behave in a dangerous manner.

“It produces paranoia, agitation, anxiety, and people do crazy things that get them into trouble,” he said. “Unfortunately, like in Colorado or Washington, we’re going to see more cannabis-induced driving impairment, accidents, and fatalities. That’s just a fact.”

What is the correct term?

George said he thinks “toxicity” would be a more appropriate word to use when speaking about cannabis cases.

“If you take too much cannabis, which is still a relatively rare thing, at least deliberately, you get more of a behavioural toxicity. So you get extremely agitated, you get psychosis, severe anxiety,” he said.

Toxicity isn’t used as often in the general public and is more popular among medical professionals, George said.

“Overdose usually means it’s an immediate effect that produces something dramatic like death or dismemberment so by that definition, I don’t think it’s correct to call it a cannabis overdose,” he explained. “It’s cannabis toxicity.”

On the other hand, Verbora said he’s not a fan of using toxicity or even self-poisoning when it comes to cannabis.

“I don’t really like those words because ‘poisoned’ sounds like something that would have a more toxic effect to the body. When you ingest poison you expect that you’re going to have stomach or kidney or liver failure or lungs or cardiovascular damage. If you consume a lot of cannabis it won’t poison any of those organs right?” he said.

Verbora said the same goes for the word “toxicity,” which suggests organ damage from consuming a toxic substance.

“You can’t have a toxic dose of cannabis,” he said.

Instead, Verbora said he thinks “overdose” may be the most correct word as long as it’s accompanied by a stipulation that it doesn’t mean it’s fatal. He added that the term “impairment” may also work to describe the effects of too much cannabis.

“If you consume too much cannabis and you get significant impairment or a cannabis overdose it can lead to a lot of cognitive and psychological side effects, so paranoia, extreme anxiety, and in very rare circumstances it can lead to hallucinations,” he said.

Verbora also said the term “greenout,” which is loosely defined as someone who becomes sick from consuming too much cannabis, has become popular among drug users, but he said he can’t foresee the medical community adjusting to that terminology.

Why you can’t die from consuming cannabis

Verbora said the reason why cannabis should be considered safer than other recreational drugs such as, opioids, cocaine, or benzodiazepines (like Xanax or Ativan), is because it doesn’t bind to any receptors in the brain stem.

“The most common reason why people overdose on substances is because they bind to special areas in the brain and the brain stem that control our respiratory system,” he explained. “They slow your ability to breathe down. That’s why they have a very potent medicinal effect because it’s actually targeting one of the most important crucial areas of the brain. The problem is if you take too much your breathing slows down so much that you stop breathing.”

Cocaine, on the other hand, can lead to fatal consequences because it affects a person’s cardiovascular system.

“It’s a very strong cardiovascular stimulant,” Verbora said. “It can put you into different arrhythmias or change your blood pressure dramatically.”

Unlike these other drugs, George said cannabis doesn’t interact with parts of the brain that control basic functions – such as breathing – which means it’s much safer.

Even if cannabis isn’t fatal, it can still cause some unpleasant side effects or lead to risky behaviour.

Both Verbora and George recommend cannabis users start slow with low dosages, particularly when consuming edibles, and increase the amount from there.

“My recommendation if you’re going to use an oral product, it should be 5 milligrams or less to start and then you should just use one product and wait 24 hours until you decide to use another edible product,” Verbora said. “If it didn’t achieve the effect you were looking for then you can move up by, on average, two to three milligrams at a time until you find a dose that works well for you.”

Recreational cannabis is set to be legal in Canada on Oct. 17, but edible products won’t be available for at least a year later as legislators continue to fine tune the regulatory details.