Five-year trends in acetaminophen use exceeding the recommended daily maximum dose

Temporal patterns of acetaminophen use exceeding the recommended daily maximum dosage of 4 g over a 5-year period (4/1/2011-3/31/2016) were evaluated in an online 1-week diary study of 14 434 adult acetaminophen users who also reported acetaminophen use in the previous month. Specific medications taken were identified by list-based prompting; respondents were not required to know their medications contained acetaminophen. Details of use were recorded daily; total daily dosage was determined programmatically. Prevalence of >4 g use over time was modelled and tested for linear changes. The overall prevalence of >4 g use (6.3% of users and 3.7% of usage days) did not change over the 5 years: odds ratio (OR) persons, 1.02 (95% CI, 0.98-1.09); OR days, 0.98 (0.92-1.05). Deviations from label directions were largely unchanged, though concomitant use increased slightly. Thus, over a recent 5-year period, there was no evidence of change in how often acetaminophen use exceeded the labelled maximum daily dose.