University of Waterloo School of Pharmacy

• “Larissa was healthy and within a week of the overdose, her liver failed, she received a liver transplant, and died from complications.
• It was probably an attempt to treat her COVID-19 symptoms at a time when she was not eating well.
• The three of us were developing educational tools on acetaminophen-related liver injury for health-care providers when we first learned of Larissa’s story.

Leading cause of acute liver injury

• Yet, it is also a leading cause of acute liver injury, which can be fatal without a rescue liver transplant.
• With millions around the world using acetaminophen every day, why are so few people aware of the dangers of overdose?
• Approximately 4,500 Canadians are hospitalized from acetaminophen overdose each year — 12 hospitalizations per day.

Toxicity and overdose

• In the first 24 hours after an overdose, there may only be mild symptoms such as nausea and vomiting, but many have no symptoms at all.
• While the liver may heal itself, around six per cent of people hospitalized for acetaminophen overdose develop liver failure.
• An antidote is available (an intravenous medicine called N-acetylcysteine) but it is most effective if given within 24 hours of overdose.

Using acetaminophen safely

• Given that acetaminophen remains one of the most common medicines for treating pain and fever, people need to take steps to reduce their risk of liver injury.
• Always check acetaminophen packages for the maximum single dose and 24-hour dose.
• If the first acetaminophen dose is taken at noon, the 24-hour window ends at noon the next day.
• When buying acetaminophen for common ailments like a headache or arthritis pain, reach for the regular strength product.