Prevalence of over-the-counter drug-related overdoses at Accident and Emergency departments in Northern Ireland--a retrospective evaluation

J Clin Pharm Ther. 2005 Feb;30(1):39-44. doi: 10.1111/j.1365-2710.2004.00607.x.


Background and objectives: One major concern associated with misuse/abuse of over-the-counter (OTC) products is the potential for over-dosage. The aim of this research study was to evaluate, over a 3-month period, OTC medicine-related overdoses (those involving OTC drugs only and OTC drugs in combination with other drugs) that led to patients presenting at the Accident and Emergency (A & E) departments in four Belfast hospitals.

Methods: A data collection sheet was designed to capture the information required from the A & E records in each hospital. A retrospective week-by-week data collection, reviewing A & E records, took place over a 3-month period (starting on 1 December 2002). All data related to cases presenting at the A & E departments because of drug overdoses (either accidental or deliberate according to Read Clinical Classification) were included in the study. Data were coded and entered into a custom designed SPSS database for analysis, using Chi square and Fisher exact tests.

Results: OTC drug-related overdoses comprised 40.1% of all overdoses, of which 24.0% were OTC-only overdoses. Those who overdosed on OTC drugs (solely or combined with other drugs) were mainly female (62.3%) and in the age category 31-50 years (44.9%; P <0.05). The majority (n=215) of OTC-related overdoses were intentional, whereas only 28 were accidental. Of those who attended the A & E departments and had an overdose history, one-third overdosed on OTC-related products and two-thirds overdosed on OTC drugs only.

Conclusions: OTC drugs accounted for a significant proportion of overdose presentations at the A & E departments in Northern Ireland. Higher awareness of the potential of OTC product use in overdose cases (intentional or accidental) is recommended for both the public and health care professionals.

Publication types

  • Comparative Study
  • Evaluation Study
  • Multicenter Study

MeSH terms

  • Acetaminophen / adverse effects
  • Age Factors
  • Alcohol Drinking / adverse effects
  • Aspirin / adverse effects
  • Data Collection / methods
  • Databases as Topic
  • Drug Combinations
  • Drug Incompatibility
  • Drug Interactions
  • Drug Overdose / epidemiology*
  • Drug Overdose / etiology*
  • Drug Prescriptions / classification
  • Emergencies / epidemiology
  • Emergency Medical Services / statistics & numerical data*
  • Female
  • Humans
  • Ibuprofen / adverse effects
  • Male
  • Nonprescription Drugs / administration & dosage
  • Nonprescription Drugs / adverse effects*
  • Northern Ireland / epidemiology
  • Retrospective Studies*
  • Self Administration / methods
  • Self Administration / statistics & numerical data
  • Social Class
  • Time Factors


  • Drug Combinations
  • Nonprescription Drugs
  • Acetaminophen
  • Aspirin
  • Ibuprofen