Adverse Event Reporting Patterns of Tobacco Cessation Medications in Korea: A Disproportionality Analysis

Background/Objectives: This study aimed to characterize adverse event (AE) reporting patterns associated with tobacco cessation medications using nationwide pharmacovigilance data from Korea. Methods: A retrospective pharmacovigilance study on tobacco cessation medications using the Korea Adverse Event Reporting System database (KIDS KAERS DB) was conducted. Descriptive analyses were performed to summarize demographic and reporting characteristics and AE patterns. Disproportionality analyses, including proportional reporting ratios (PRR), reporting odds ratios (ROR), and information components (IC), were performed to detect potential signals of disproportionate reporting. Results: A total of 779 individual case safety reports (ICSRs) involving tobacco cessation medications were included. Nicotine replacement therapy (NRT) accounted for 606 ICSRs (77.79%), followed by varenicline (n = 150, 19.26%) and bupropion (n = 23, 2.95%). Age information was unavailable for 558 ICSRs (71.63%). Among ICSRs with documented age information, the 50-59-year age group was the most frequently represented. Fifty-two serious ICSRs (6.68%) were identified, comprising 49 ICSRs involving NRT and 3 involving bupropion. SOC-level disproportionality analyses identified signals of disproportionate reporting for psychiatric disorders for bupropion and psychiatric and gastrointestinal disorders for varenicline. All identified signals remained detectable after excluding reports involving individuals aged <18 years, whereas causality-based restriction altered the detected signal patterns. Conclusions: This nationwide pharmacovigilance study identified medication-specific adverse event reporting patterns across NRT, bupropion, and varenicline. While these findings do not establish causal relationships, the observed differences in reporting patterns provide pharmacovigilance insights into the post-marketing reporting patterns of tobacco cessation pharmacotherapies and support further evaluation using pharmacoepidemiologic studies with appropriate exposure denominators.