Health Canada has told makers of over-the-counter products to provide clearer label instructions and stronger warnings on products containing acetaminophen in an effort to prevent liver damage.

Acetaminophen is used safely by the vast majority of Canadians, the regulator said in making the announcement Thursday.

But it comes with risks, especially if taken for longer than directed. These risks include liver damage, which in severe cases can lead to liver failure and death.

Acetaminophen is commonly associated with Tylenol. More than 475 different acetaminophen products are authorized for sale in Canada, the majority being non-prescription. These include combination products such as NyQuil and NeoCitran, as well as prescription medications.  

Some of the instructions will warn consumers to:

  • Use the lowest effective dose.
  • Not exceed four grams for adults in a 24-hour period.
  • Use these products for no more than five days for pain or three days for fever.
  • Avoid mixing them with alcohol if drinking three or more drinks in a day.

Makers will be required to highlight that a product contains acetaminophen in bold, red lettering on the front of the package and to provide calibrated devices for all liquid children's products. 

Acetaminophen has been sold in Canada since 1961, said Dr. Supriya Sharma, senior medical adviser with Health Canada's health products and food branch in Ottawa.

Check the label

"When it's in as many products as it is, and when people have a familiarity with the products, there may be less of a likelihood that somebody will actually read the label," Sharma told reporters.

The label changes are effective immediately for all new products and within 18 months for existing ones.

A new drug facts table will also be required for packages to provide product instructions, warnings and other safety information in a consistent, quick-reference format, effective 2021.

The changes are based on the regulator's safety review on the drug released last year. 

Health Canada's 2015 Acetaminophen Report showed more than 250 cases of serious liver injury every year related to acetaminophen. 

About 20 per cent of the cases are due to people exceeding the recommended dose unintentionally. In many of these cases, patients had identifiable risk factors for acetaminophen liver injury, such as alcoholism or viral liver disease, according to the report.

'Death by Tylenol'

Dr. Eric Yoshida is a liver specialist at Vancouver General Hospital, where he regularly sees patients from across British Columbia and Yukon with severe liver failure from inadvertent acetaminophen overdoses.

"We've had patients who have died waiting for liver transplantation, a transplant that never came," said Yoshida, who is also chair of the Canadian Liver Foundation's medical advisory committee. "They're in our ICU with acute liver failure and the cause is inadvertent Tylenol injury — death by Tylenol. This is completely avoidable. I'm all in favour of increased public awareness and better labelling."

Yoshida would like to see the amount of acetaminophen in each capsule or tablet limited to the regular strength dose of 325 milligrams, rather than the 500 milligrams found in extra-strength products. Otherwise, people may not be aware they're taking 1,000 milligrams from two extra-strength pills. 

In the United Kingdom, regulators have talked about limiting the number of acetaminophen tablets per package, said Dr. Michael Rieder, who holds a chair in pediatric pharmacology at Western University in London, Ont.

In the case of baby Aspirin for example, there's good Canadian data to show that a limited-package-size approach worked, Rieder said. 

Overall, Rieder called Health Canada's acetaminophen label changes sensible. But he'd also like to see the top dose per tablet reduced from the current 500 milligrams in extra strength products.

"Extra strength isn't always extra value," Rieder said in an interview. 

Acetaminophen Drug Facts table

The Drug Facts Table will be required on all products in Canada by 2021. (Health Canada)

Sharma said Health Canada heard concerns from patient groups who feared that limiting the daily maximum dose or restricting access to extra-strength formulations of acetaminophen could drive patients towards opioids and other pain medications with more serious side-effects on the liver or kidneys. She added the issue didn't come up in the regulator's review of the medical or scientific literature. 

Health Canada also plans to spread the word about the label changes through social media channels. Industry initiatives, such as Tylenol Canada's Get Relief Responsibly and the Know your Dose program in the U.S., also play a role, Sharma said.