Prevalence of exceeding maximum daily dose of paracetamol, and seasonal variations in cold-flu season

AIMS: To estimate prevalence of excess intake of paracetamol and investigate seasonal variations therein. METHODS: Between 2011 and 2016, 14 481 US adults who used paracetamol in the preceding 30 days were sampled from national online panels and completed a detailed online daily diary of paracetamol medication use for 7 days. Respondents were not told that the study concerned paracetamol. Cold/flu season (CFS), identified using Google Trends data, was contrasted to off‐season in symptoms, use of paracetamol medications, and consumption exceeding 4 g (the recommended daily maximum). RESULTS: Overall, 6.3% [95% confidence interval: 5.9–6.7%] of users exceeded 4 g on at least one day; 3.7% [3.5–3.8%] of usage days exceeded 4 g. Cold/flu symptoms were more likely to be experienced and treated with paracetamol in CFS than off‐season. Paracetamol users were more likely to exceed 4 g during CFS (6.5% vs. 5.3%; odds ratio = 1.24, 1.04–1.48); days exceeding 4 g also increased (3.9% vs. 2.8%; odds ratio = 1.37, 1.11–1.69). This was not due to differences in characteristics of individuals using paracetamol in CFS, but primarily to increased use of over‐the‐counter combination medications designed to treat upper respiratory cold/flu symptoms (33.2% of usage days in CFS vs. 24.8% in off‐season; odds ratio = 1.58, 1.46–1.72). When such medications were omitted, there was no statistically significant seasonal variation in exceeding 4 g. CONCLUSIONS: Paracetamol use and over‐dosing increases in CFS, primarily due to increased use of over‐the‐counter combinations treating upper respiratory cold/flu symptoms. Pharmacists should warn users to follow labelled dosing directions, especially during CFS.