Pattern of adverse drug reactions reported through VigiFlow at a tertiary care teaching hospital in North India: a retrospective analysis

Background: To analyse adverse drug reactions (ADRs) reported to the VMMC & Safdarjung Hospital, New Delhi, entered into VigiFlow analysing causality, severity, preventability and outcome. Methods: Individual case safety reports (ICSRs) entered into VigiFlow from March 2021 to March 2026 were retrospectively reviewed. Reports lacking a documented suspect drug and reaction term were excluded as incomplete. Complete reports were analysed for demographics, system organ class (SOC), suspect drug classes, causality (WHO-UMC and Naranjo scales), severity (Modified Hartwig and Siegel scale), preventability (Schumock and Thornton criteria) and outcome. Results: Of 974 ICSRs, 925 (95.0%) were evaluable. Mean age was 38.9±17.6 years; 54.2% were male. Gastrointestinal (27.4%), skin/subcutaneous (25.1%) and general/administration-site disorders (20.1%) were most affected. Antimicrobials (24.0%), antineoplastics (13.1%) and cardiovascular drugs (11.4%) were leading suspect classes. WHO-UMC causality was probable/likely (73.4%) or possible (25.7%), with similar Naranjo findings. Reactions were mostly mild (63.4%) or moderate (29.8%); 6.8% were severe and 8 (0.9%) fatal, six linked to antineoplastic chemotherapy. Preventability was noted in 88.6%; recovery was documented in 44.6%. Conclusions: Antimicrobials, antineoplastics and cardiovascular drugs predominated among ADRs, most being probable, mild-to-moderate and preventable. Strengthening dose monitoring, allergy screening, drug-interaction checks and ICSR completeness may reduce ADR burden, especially in oncology and radiocontrast use.