Evaluation of valganciclovir's neutropenia risk in pediatric solid organ transplant recipients utilizing two dosing regimens.

Background: Valganciclovir is approved for cytomegalovirus prophylaxis in pediatrics using the Pescovitz algorithm. There are reports of valganciclovir overdoses in children with low body surface area and overestimated creatinine clearance utilizing this algorithm. This study compared the incidence of neutropenia and cytomegalovirus infection between the Pescovitz and weight-based dosing algorithms.

Methods: A single-center retrospective chart review from January 2010 to September 2018 was performed on pediatric heart, liver, and kidney transplant recipients, who received valganciclovir. Data were collected from the initiation of valganciclovir prophylaxis to 30 days after discontinuation. The primary objective was the incidence of neutropenia in patients receiving valganciclovir dosed by the Pescovitz versus weight-based dosing algorithms.

Results: This study included 187 pediatric transplant recipients who received valganciclovir dosed via the Pescovitz (62 recipients) or weight-based dosing algorithms (125 recipients). The incidence of neutropenia was higher in the Pescovitz (69.4%) compared to the weight-based dosing group (53.6%; p = .04) including moderate and severe neutropenia. Cytomegalovirus viremia was not significantly different between the two groups and occurred in 4.8% of the Pescovitz group compared to 2.4% of the weight-based group (p = .4).

Conclusions: The incidence of neutropenia was greater in recipients receiving valganciclovir dosed via the Pescovitz algorithm compared to the weight-based dosing. There were no significant differences in regard to cytomegalovirus viremia or disease between the two groups.