Investigation of Efficacy of Improved Acetaminophen Labeling

Acetaminophen is a pain reliever and fever reducer found in many over-the-counter (OTC)
analgesics as well as prescription (Rx) products commonly prescribed at discharge from the
emergency department. 1 An estimated 36% of Americans ingest acetaminophen at least once a
month.1, 2 While acetaminophen is generally safe and effective when used at recommended
doses, acetaminophen overdose has surpassed viral hepatitis as the leading cause of acute
liver failure (ALF) in the United States.2-4 Moreover, one half to two-thirds of overdoses
leading to acute liver failure are unintentional, suggesting the root cause may be poor
understanding of medication labeling or failure to recognize the consequences of exceeding
the recommended maximum daily dosage.2-4 On-going studies by this research group have shown
patient misunderstanding of dosing instructions and warnings associated with OTC medicines
to be prevalent.

It has also been suggested that patients receiving prescription medications containing
acetaminophen may not be informed or aware of the potential risk of acetaminophen overuse
when taking prescription products in combination with over-the-counter pain relievers.1
This is supported by the finding that a third of narcotic users were simultaneously using an
OTC acetaminophen containing product in a multicenter study of ALF cases.2 To address the
growing concern of acetaminophen misuse, in June 2009 the US Food and Drug Administration
(FDA) convened a panel to discuss the maximum dose recommendations of acetaminophen found in
OTC medications. The panel concluded that there was a notable lack of available evidence on
consumer understanding and use of over-the-counter acetaminophen products. Studies are
needed to explore patients' 1) knowledge of potential acetaminophen overdose when using
prescription analgesics simultaneously with non-prescription acetaminophen and 2) avenues
available to increase awareness of potential acetaminophen overdose from misuse of both OTC
and Rx acetaminophen containing medicines.

Inclusion Criteria:

- 18-80 years old

- English speaking

Exclusion Criteria:

- Visual or hearing impairments

- Moderate to severe cognitive impairments