Risk of Unintentional Overdose with Non-Prescription Acetaminophen Products

Abstract

BACKGROUND: There is increasing concern over the risk of consumer unintentional misuse of non-prescription (a.k.a. 'over-the-counter') medications containing acetaminophen, which could lead to acute liver failure. OBJECTIVE: To determine the prevalence of potential misuse and overdose of over-the-counter medications containing acetaminophen, either alone or in combination. DESIGN: Cross-sectional, structured interviews with literacy assessment. SETTING: One academic and one community-based general internal medicine practice in Chicago, IL, and one academic general internal medicine practice and a public hospital clinic in Atlanta, GA. PATIENTS: Five hundred adults seeking primary care, ages 18-80. MEASUREMENT: Demonstration of how and when patients would take over-the-counter medications containing acetaminophen, alone or in combination with one another, over a 24-hour period. RESULTS: Overall, 23.8 % of participants demonstrated they would overdose on a single over-the-counter acetaminophen product by exceeding a dose of four grams in a 24-hour period; 5.2 % made serious errors by dosing out more than six grams. In addition, 45.6 % of adults demonstrated they would overdose by 'double-dipping' with two acetaminophen-containing products. In multivariable analyses, limited literacy (Relative Risk Ratio (RR) 1.65, 95 % Confidence Interval (CI) 1.03-2.66) and heavy acetaminophen use in the past six months (RR 1.70, 95 % CI 1.10-2.64) were independently associated with overdosing over-the-counter products. CONCLUSION: Misunderstanding of the active ingredient and proper instructions for over-the-counter medications containing acetaminophen is common. The potential for errors and adverse events associated with unintentional misuse of these products is substantial, particularly among heavy users of acetaminophen and those with limited literacy.

Variability in Acetaminophen Labeling Practices: a Missed Opportunity to Enhance Patient Safety

“…Standards or recommendations from organizations like United States Pharmacopeial Convention (USP) are often not implemented until State Boards and/or the FDA adopt them into their regulations. Recent voluntary guidance by the FDA may provide assurances that acetaminophen be spelled out on primary labels, but our research shows this might not be sufficient as a stand-alone strategy to prevent harm to patients [10]. This study demonstrates the importance of the FDA and State Boards of Pharmacy to set a single, clear standard for labeling acetaminophen as an active ingredient and require uniform warnings about concomitant use of acetaminophencontaining products.…”

“…Previous investigations, including research by our team, have shown that patients may misinterpret drug labels and cannot recognize acetaminophen as an active ingredient [9,10], which may facilitate unintentional overdoses. The objective of this manuscript is to describe the prescription labeling practices for common acetaminophen-containing analgesics, specifically focusing on how active ingredient information and concomitant use warnings were conveyed.…”

“But it's just paracetamol”: Caregivers’ ability to administer over-the-counter painkillers to children with the information provided

“…Studies have found that those who use written sources of information have increased knowledge about the medication, and yet less than half of the consumers can fully understand this information [1]. The worldwide increase over the last 15 years in the use and overuse of OTC medication [2][3][4][5][6][7] has resulted in a critical need to assess the current process of informing OTC medication users of the correct dosage and potential health risks. Specifically, there is a need to identify whether consumers' health literacy can be improved upon, to reduce risks from selfmedicating or medicating children in contradiction to the label instructions.…”

Improved Label and Liver Warning for Nonprescription Acetaminophen Products

“…Yet, recent assessments of consumers' decisions about acetaminophen-taking behavior indicate substantial misunderstanding of label instructions relating to exceeding the maximum recommended daily dose and using 1 product containing acetaminophen. 14 On this background, we investigated a revised acetaminophen over-the-counter (OTC) Drug Facts label (ODFL) to determine consumers' use of and preference for a reorganized format with a revised warning heading and inclusion of early signs of liver damage.…”