Good use and knowledge of paracetamol in self-medicated patients: Regional prospective study in community pharmacies

Abstract

Paracetamol, the highest over-the-counter (OTC) selling drug in France, has become the first cause of acute hepatic failure [1] . Patient's knowledge of paracetamol has to date only been assessed in hospitalized patients. We aimed to assess good use and knowledge of paracetamol in patients in a realistic setting of self-medication in our region. We conducted a prospective observational study in randomly selected community pharmacies of Metz (France) agglomeration. Patients coming to buy OTC paracetamol for themselves or their family had to answer to an anonymous auto-questionnaire. After being asked about gender, age, weight, parenthood and chronic disease, the patient had to answer to 14 items about paracetamol indications, recommended maximal dose per intake and maximal daily dose, delay between 2 doses, consequences of overdosage and alcohol intake, and the need to adapt dosage to the body weight. The patient also had to identify drugs containing paracetamol among 6 usual drugs; and finally to tell how he gets information and circumstances that can lead him to stop self-medication and visit his general practitioner. Responses were individually and concomitantly analyzed through 3 scores: good use (5 points; good user if > 3), overdosage (4 points; positive if ≤ 3) and knowledge (9 points; good knowledge if > 6). Univariate and multivariate analysis were performed with SAS, version 9.3 (SAS Institute, Cary, NC). Twenty-four community pharmacies participated and 302 individual questionnaires were collected. Most of patients (84.4%) could be considered as “good users”. Independent factors of good use were a good knowledge of paracetamol (OR = 5.3; p < 0.0001) and more surprisingly, the fact of having no children (parenthood: OR = 0.1; p = 0.006). Responses corresponding to involuntary overdosage was mostly due to a too short interval between drug intakes (3 hours). Only 30.8% of patients were aware of liver toxicity of paracetamol and only 40.7% knew the risk of the association with alcohol. Both good use and knowledge were significantly higher in patients looking for information from their pharmacist, physician and package leaflet. Patients should be better informed about hepatotoxicity of paracetamol to warrant a better safety of its consumption by self-medication. Pharmacists and physicians have to remind patients the risk factors of unintentional overdose and liver toxicity and not hesitate to check if the patient may be at risk for overdosage. Package leaflets should also to be more informative.