title: Frequency and severity of adverse drug reactions due to self-medication: a cross-sectional multicentre survey in emergency departments.
abstract: BACKGROUND
  Little is known about the relation of adverse drug reactions (ADRs) to self-use of medications.
  
  
  OBJECTIVE
  The aim of this study was to determine the frequency and severity of ADRs related to self-medication (ADR-SM) among emergency department (ED) patients and to describe their main characteristics.
  
  
  METHODS
  A prospective, cross-sectional, observational study was conducted over a period of 8 weeks (1 March to 20 April 2010), in the ED of 11 French academic hospitals. Adult patients presenting to the ED during randomization periods were included, with the exception of cases of self-drug poisoning, inability to complete self-medication questionnaire, or refusal. Clinical outcomes were assessed as well as history of self-medication behaviours and all drugs taken. All doubtful files and those related to ADR-SM were systematically reviewed by an expert committee.
  
  
  RESULTS
  A total of 3,027 of 4,661 patients presenting to the ED met the inclusion criteria. Of these, 84.4 % declared a self-medication behaviour, 63.7 % took at least one non-prescribed drug during the previous 2 weeks and 59.9 % took a prescribed medication. A total of 296 patients experienced an ADR (9.78 %), of which 52 (1.72 %) were related to self-medication. Those ADRs related to self-medication included prescribed drugs (n = 19), non-prescribed drugs (n = 17), treatment discontinuation (n = 14), and interactions between non-prescribed and prescribed drugs (n = 2). The ADRs attributed to non-prescribed drugs represented 1 % of all patients taking non-prescribed drugs (n = 1,927). ADR severity was significantly lower for those related to self-medication (p = .032).
  
  
  CONCLUSIONS
  Self-medication is frequent; its potential toxicity should not be neglected, taking into account the rate of adverse drug reactions in about 1 % of ED patient.
authors.affiliation: EA 3826, Faculté de Médecine, 1 rue Gaston Veil, 44035, Nantes, France, nathalie.asseray@chu-nantes.fr.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Asseray
authors.forename: Françoise
authors.initials: F
authors.lastname: Ballereau
authors.forename: Béatrice
authors.initials: B
authors.lastname: Trombert-Paviot
authors.forename: Jacques
authors.initials: J
authors.lastname: Bouget
authors.forename: Nadine
authors.initials: N
authors.lastname: Foucher
authors.forename: Bertrand
authors.initials: B
authors.lastname: Renaud
authors.forename: Lucien
authors.initials: L
authors.lastname: Roulet
authors.forename: Gerald
authors.initials: G
authors.lastname: Kierzek
authors.forename: Aurore
authors.initials: A
authors.lastname: Armand-Perroux
authors.forename: Gilles
authors.initials: G
authors.lastname: Potel
authors.forename: Jeannot
authors.initials: J
authors.lastname: Schmidt
authors.forename: Françoise
authors.initials: F
authors.lastname: Carpentier
authors.forename: Patrice
authors.initials: P
authors.lastname: Queneau
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D004366:Nonprescription Drugs; D011446:Prospective Studies; D012651:Self Medication / Q000009:adverse effects*
chemical_list: D004366:Nonprescription Drugs