Introduction:
Safety data regarding remdesivir in pediatric populations remain limited, particularly for those with complex comorbidities. This study evaluated the hepatic and systemic safety of remdesivir in hospitalized children with COVID-19 by comparing treated patients to a control group receiving no antiviral therapy.

Material and methods:
This single-center, retrospective case-control study included 76 hospitalized children: 42 children treated with remdesivir and 34 controls. Clinical and laboratory parameters, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), bilirubin, creatinine, and C-reactive protein were asse- ssed at baseline and at peak during hospitalization. Clinical severity was evaluated using the World Health Organization clinical progression ordinal scale. To isolate treatment-emergent hepatotoxicity, patients presenting with baseline transaminase elevations > 2 × the upper limit of normal (ULN) were excluded from hepatic sub-analyses.

Results:
The treated group was significantly older (median 12.3 vs. 2.3 years; p < 0.001) and required longer hospitalization (median 10 vs. 5 days; p < 0.001). Baseline disease severity was comparable (p = 0.173), though all patients requiring mechanical ventilation were in the treated cohort. Peak ALT and AST values were significantly higher in the remdesivir group (ALT: 51.0 vs. 22.5 U/l, p = 0.006; AST: 47.0 vs. 38.0 U/l, p = 0.033). Treatment-emergent ALT elevation > 2 × ULN occurred in 19.0% of treated patients vs. 5.9% of controls (p = 0.039). However, all elevations were transient and not associated with clinically significant hepatic dysfunction or treatment discontinuation. No significant differences were observed in bilirubin or creatinine levels between groups. Mortality (7.1%) occurred only among critically ill patients with severe comorbidities and was not attributed to remdesivir toxicity.

Conclusions:
Remdesivir is associated with transient, manageable elevations in liver enzymes but demonstrates a favorable safety profile in hospitalized children. These findings support its use in pediatric COVID-19 management, even among those with significant underlying comorbidities.