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What is aconite poisoning? Toronto doctors explain


As many as 12 people were forced to seek medical attention after ingesting what officials suspect to be aconite at a restaurant in Markham, Ont. over the weekend.

York Region’s Medical Officer of Health, Dr. Barry Pakes, spoke Tuesday morning on the mass poisoning, which took place at Delight Restaurant & BBQ at Castlemore Avenue and Markham Road.

While Pakes could not speak to the condition of the patients, he confirmed four remain “seriously ill” in intensive care units.

“We do suspect that it was … aconite,” Pakes said, adding that testing is currently underway to confirm the cause of the adverse reactions.


Aconite is a substance found in Aconitum plants, also known as Monkshood or Wolfsbane, and can be found widely across the Northern Hemisphere, Dr. Prateek Lala, associate director of applied clinical pharmacology at the University of Toronto, told CTV News Toronto Tuesday.

All parts of the plant are toxic, he explained, but the compound aconitine is particularly deadly.

“The lethal dose for humans can be as little as two milligrams, or the size of a sesame seed,” Lala said.

A plant in the Aconitum family can be seen above. (Wiki Commons)


Symptoms can vary depending on how much is ingested and the size of the person who ingested it, Lala said.

“The symptoms that people feel after consuming usually start within 30 to 60 minutes, so a much shorter timeframe than you would see with typical food poisoning,” he said.

On Monday, Dr. David Juurlink, head of clinical pharmacology and toxicology at Sunnybrook Health Sciences Centre, took to social media to warn the public of the potential poisoning event, and what symptoms to watch for.

“Effects occur quickly and are chiefly [gastrointestinal] , neurologic and cardiac,” he wrote.

Juurlink warned the public to monitor for nausea, vomiting, cramping, numbness in the face and mouth area that could progress to the limbs, and muscle weakness.

Symptoms at the later stages of aconite poisoning can include low blood pressure, cardiac arrhythmias and coma. If enough is ingested, it can be fatal.

“It doesn't take a lot for this to have a significant effect,” Lala said.


There is no one cure for aconite poisoning, both doctors said.

“Most of the therapies and treatments for this are supportive,” Lala explained. “There are medications that can be used to support heart rhythms and blood pressure and things like that, but for the most part, it's a game of watching and waiting to see how things progress.”

Some patients require ventilation to help support their breathing while they recover.

While there’s no standardized timeline, those who recover from the poisoning will do so in a matter of days, Lala said.


While raw aconite can be deadly, and risk remains high if ingested, Aconitum plants have been used in Traditional Chinese Medicine for thousands of years.

When used in Traditional Chinese Medicine, the toxins within acotinum plants can be decomposed into less or non-toxic derivatives using Chinese processing methods known as Pao Zhi.

Aconite can also sometimes be mistaken for ginger powder, as the roots of both plants are visually similar.

In March, a health authority in British Columbia issued a warning after a batch of sand ginger powder bought at a Burnaby mall was found to potentially have aconite in it.

Lala underlined that, at this time, there is no information available as to whether the incident in Markham was accidental or intentional.

Anyone who ate at Delight Restaurant and BBQ on Aug. 27 or 28 and is experiencing any of the symptoms listed above is being encouraged to seek immediate medical attention. Top Stories


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