LAUSR

Prophylaxis with valganciclovir (VGCV) is used routinely to prevent cytomegalovirus (CMV) infections in at‐risk pediatric solid organ transplant (SOT) recipients. However, the rate and factors associated with toxicities in this population are not well‐described. We conducted a retrospective cohort study of children undergoing SOT at our hospital from January 2012–June 2018. We evaluated the frequency of hematologic and renal toxicities from day 15 through 1‐year post‐SOT in relation to antiviral exposures, focused on VGCV prophylaxis. Marginal rate models were used to determine the risk of kidney injury and neutropenia in relation to VGCV prophylaxis. Among 281 SOTs, VGCV prophylaxis was administered on 20.1% of all follow‐up days. The incidence rates of kidney injury, leukopenia, and neutropenia were significantly higher during VGCV prophylaxis compared to when no antiviral agents were given. Using multivariable marginal rate models, receipt of VGCV prophylaxis was associated with development of kidney injury (rate ratio [RR] 1.79, 95% confidence interval [CI]: 1.22–2.65) and neutropenia (RR 4.82, 95% CI: 3.08–7.55). VGCV dosing did not impact the development of kidney injury or neutropenia. Toxicities are common with VGCV prophylaxis in pediatric SOT recipients.