Adverse Drug Reactions With Common Antivirals in Viral Hepatitis: A Prospective Observational Study From a North-Indian Tertiary-Care Opd

Background: Antiviral therapy is central to viral hepatitis care, yet real-world adverse drug reaction (ADR) patterns in busy outpatient settings remain incompletely characterised. Aim: To evaluate ADRs associated with antivirals used for viral hepatitis, focusing on frequency, severity, time-to-onset, and causality. Materials and Methods: A prospective, observational study conducted in the Gastroenterology and Medicine outpatient departments of KGMU, Lucknow after ethics approval (IEC 3006/Ethics/2024, 23-01-2024). Adults with viral hepatitis receiving antivirals were enrolled (n = 95) after consent. ADRs were captured using a pre-designed case-record form and assessed by WHO-UMC causality and Hartwig severity scales; follow-up was scheduled at ~1 month and thereafter per protocol, with review after any ADR. Statistical analyses included paired t-tests, chi-square tests, and Kruskal–Wallis (two-sided p < 0.05). Results: Antivirals prescribed were tenofovir, entecavir, sofosbuvir+daclatasvir and sofosbuvir+velpatasvir. From baseline to follow-up, there were significant improvement in biochemical parameters, decrease in AST/SGOT, ALT/SGPT, ALP, urea, creatinine, and INR, and increase in serum protein and albumin. ADRs occurred in 31/95 (32.6%); Most frequent ADRs were nausea, headache, and fatigue. Most ADRs were mild. Causality was probable/possible in all cases. Conclusion: In tertiary-care practice, antiviral therapy for viral hepatitis was associated with favourable biochemical trajectories & mild ADRs. ADR type & onset timing differ, supporting early monitoring & standardised documentation to optimise safety.