The dark side of acetaminophen

Globally, acetaminophen (or paracetamol, as it is known in many other countries) is the No. 1 ingredient suspected in drug-induced liver injury deaths, Health Canada noted in its 2009 report, citing a World Health Organization adverse drug events database.

Health Canada has been more worried about acetaminophen than many Canadians may realize.

“Definitely there’s a concern (with acetaminophen),” said Sharma in a phone interview. “The challenge is we’ve got a product that’s been on the market for a long period of time.”

“That’s why we’re doing as much as we are.”

But none of the acetaminophen researchers, toxicologists or drug safety experts contacted by the Star knew about Health Canada’s working group or the upcoming report. Lunney - who petitioned Parliament for stronger acetaminophen warnings seven years ago - also didn’t know what Health Canada has been doing on this issue.

In 2006, a couple from Lunney’s riding, Chuck and Tammie Campbell, received a phone call from their daughter’s roommate: something was wrong with Ashley.

Their daughter Ashley, then 19, was going through a typical teenage phase: she was arguing with her parents, had moved into her own apartment and was struggling with boy troubles.

At Ashley’s apartment, they discovered their daughter dazed and confused. An empty bottle of Tylenol was in the bathroom; Ashley said she had “taken Tylenol and nothing else.”

At the hospital, Ashley told her parents she wanted to get better. It never occurred to them that she would not - until the doctor told them Ashley’s liver had been destroyed.

Blood tests revealed alcohol and cocaine in Ashley’s system. But the doctors said it was the Tylenol that was killing her.

“Tylenol!!! Regular strength, over-the-counter, buy it by the bushel load, Tylenol,” Campbell wrote on a website created in the memory of his daughter. “My head was reeling - I had been a policeman for 25 years and never heard of such a thing.”

Ashley’s death took three agonizing days. Her father remembers how her brain swelled, her organs shut down and her blood stopped clotting. Ashley would shake and bolt upright, screaming in pain. Everything swelled; her belly, filled with gas that released in “long awful belch-like bursts of air”; her tongue, so thick her mouth couldn’t close; her eyes, which oozed with “red-yellow goo.”

The coroner who investigated Ashley’s death noted her history of depression and her claim to have taken Tylenol “in response to sudden despondency over some personal issues.” But Ashley “later adamantly denied this was her intention,” Dr. David Sherstone wrote in his coroner’s report. “As her intentions were not clear, an accidental overdose cannot be ruled out.”

Sherstone ultimately classified Ashley’s death as accidental. Her father agrees and insists Ashley never wanted to die; her last words to her mother were: “I love you, too, Mom and I’m fighting for you.”

Chuck Campbell doesn’t think Ashley understood the risks of Tylenol. At the time of her death in 2006, acetaminophen labels only warned that “it is hazardous to exceed the maximum recommended dose unless advised by a physician.”

Campbell was shocked to discover that in British Columbia, acetaminophen was the No. 1 pharmaceutical involved in intentional and unintentional drug poisonings.

“We realized we had to do something,” Campbell said. “It’s just wrong and people don’t know.”

He reached out to Lunney, who presented two petitions to the House of Commons in 2007 and 2008, calling for stronger warning labels on acetaminophen products. In March 2008, Tony Clement, then Canada’s health minister, responded by stating that acetaminophen labels were under review and new rules would soon be released.

One year later, the current “Acetaminophen Labelling Standard” came into effect. Today, acetaminophen labels carry clearer warnings (“Taking more than the maximum daily dose may cause severe or possibly fatal liver damage”), caution against combining products (“DO NOT USE with other drugs containing acetaminophen”) and instruct consumers to take two pills only if the first dose of a single tablet didn’t work.

Lunney’s petitions also triggered Health Canada to search its adverse reactions database, which is voluntary and cannot be used to prove causality. This resulted in a 48-page internal report in 2009 called “Special Project: Acetaminophen and Hepatoxicity,” which the Star has obtained.

Health Canada found 115 reports of adverse drug reactions associated with acetaminophen over five years. Most were associated with suicide attempts, intentional overdoses or alcohol abuse - but 39 cases were not and 16 of these were fatal.

The health agency also discovered a dozen instances where people suffered liver injuries after taking doses of less than four grams, the daily recommended maximum, for between one and 60 days. Six of these people suffered serious liver injury or failure.

For the Health Canada department responsible for monitoring drug safety, these findings prompted them in July 2009 to recommend changing acetaminophen labels to warn of “severe or even fatal LIVER INJURY, even at doses less than the maximum recommended dose” (emphasis theirs).

This language has never appeared on Canadian labels.

They also recommended clarifying the risk of combining acetaminophen products, as well as listing the symptoms of overdose: “nausea, vomiting, weakness, excessive sweating, anorexia, abdominal pain, or pale lips, tongue, mouth, palms, or impaired cognition.”

These recommendations were not adopted.

Health Canada has not explained why it chose not to adopt the recommendations. According to Gerry Harrington of Consumer Health Products Canada, the recommendations were opposed by representatives of non-prescription drug manufacturers, who participated in Health Canada’s labelling review.

Harrington said there were many heated conversations with Health Canada, as industry representatives felt too many “really low-probability scenarios” were being proposed.

“The worry was, how do you get all of that on the label without it being absolutely unreadable?” Harrington said. “We were saying . . . is it really prioritizing the risks in the consumer’s mind?’”

Since 2010, the acetaminophen working group has been collecting evidence on the drug’s safety and working to pin down Canadian statistics.

The Star has obtained two versions of the working group’s “key scientific questions” that guides its research. They indicate the matters of greatest urgency for Health Canada, including:

- How many emergency room visits, hospitalizations and deaths related to acetaminophen overdoses happen every year in Canada?
- Are certain groups more at risk when it comes to acetaminophen?
- Should the maximum daily dose be changed - and “how did 4,000 mg become the standard dose”?

“You would think that after (50 years) of availability, they would have already addressed these topics long ago,” said Dr. David Juurlink, a toxicologist and drug safety expert with Sunnybrook hospital.

“I’m glad they’re paying attention to it but it’s something that warranted attention a few decades ago.”

In the United Kingdom, acetaminophen is the most common drug taken in overdose - mostly in suicides - and stores that aren’t pharmacies can only sell the drug in packages of up to 16 extra-strength pills. In other European countries, such as Germany and France, acetaminophen can only be purchased in pharmacies - and never in the 100- or 200-pill bottles available in Canada.


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