Comparative Analysis of Ethical-the-counter Drugs and Over-the-counter Drugs for the Adverse Events from the Community Pharmacy

ABSTRACT

OBJECTIVE: To compare adverse event reporting patterns between ethical-the-counter and over-the-counter drugs from community pharmacies and outpatient settings. METHODS: We conducted a descriptive study using the adverse event reporting database, wherein data were collected from the regional pharmacovigilance centers of the Korean Pharmaceutical Association between January 1, 2016 and December 31, 2016. The reported drugs were classified into either ethical-the-counter or over-thecounter drugs, and we compared the distribution of patient age and gender, frequent adverse events and medications, serious adverse events, and causality assessment results, where causality assessments were performed according to the World Health Organization-The Uppsala Monitoring Centre's system. RESULTS: We included 17,570 reports (75,451 drug-adverse event pairs). Ethical-the-counter and over-the-counter drugs accounted for 81.4% and 18.6% of the total adverse event reports, respectively. The use of over-the-counter drugs was higher in females and patients aged 65 years. Alimentary tract and metabolism drugs, and respiratory system drugs were the most frequent ethical-the-counter and over-the-counter drugs, respectively. From causality assessment results, “possible” (75.4%) was the most commonly assigned category for ethical-the-counter drugs, while “possible” (44.0%) and “unlikely” (47.7%) were the most common categories for over-the-counter drugs. The distribution of serious adverse events were similar for both ethical-thecounter and over-the-counter drugs. CONCLUSION: Differences were observed in age, gender, reported medications, and symptoms for both ethical-the-counter and over-the-counter drugs. Further pharmacovigilance activities considering the adverse event characteristics of over-the-counter drugs, which are comparable to ethical-the-counter drugs, should be performed.