Preventability of Antibiotic-Associated Adverse Drug Reactions Reported to a Regional Pharmacovigilance Center: A Cross-Sectional Descriptive Study

Background Antibiotic-associated adverse drug reactions (ADRs) are a major contributor to medication-related harm and healthcare burden. Data on their preventability in Vietnam remain limited. Objectives To characterize the severity, implicated drug classes, and preventability of antibiotic-related ADRs reported to the Ho Chi Minh City DI & ADR Center in 2023. Methods A cross-sectional descriptive study was conducted using retrospective data of all ADR reports involving antibiotics from January–December 2023. Causality was assessed using the WHO-UMC criteria, severity according to clinical outcomes, and preventability using the WHO P-method. Results Among 3,307 ADR reports, 1,437 (43.5%) involved antibiotics; 1,403 (97.6%) had a confirmed causal relationship. Most ADRs were non-serious (66.9%). Skin and subcutaneous tissue disorders (68.1%) and rash (42.4%) were the most common manifestations. Other beta-lactams (52.1%) and fluoroquinolones (13.4%) were the leading causative drug classes, with ceftriaxone most frequently reported. Fifty-seven cases (4.1%) were preventable, most commonly due to inappropriate route of administration (31.6%), history of hypersensitivity (26.3%), or failure to adjust for patient characteristics (24.6%). Conclusion Antibiotic-related ADRs accounted for a substantial proportion of regional ADR reports, predominantly involving broad-spectrum beta-lactams. The proportion of preventable ADRs was lower than reported in previous studies, likely reflecting underreporting in spontaneous reporting systems. Strengthening antibiotic stewardship, electronic prescribing alerts, and healthcare worker training may reduce preventable ADRs and support safer antibiotic use.