Effect of Calcineurin Inhibitor Initial Dosing on Drug Levels in Pediatric Stem Cell Transplant Recipients

Purpose: Calcineurin inhibitors are used to prevent graft versus host disease in allogeneic stem cell  transplant recipients. Achieving therapeutic drug levels prior to transplant engraftment decreases the development of graft versus host disease. The objective of this study is to investigate if higher initial dosing of calcineurin inhibitors results in a shorter time to therapeutic drug levels.

Methods: This study, approved by the Institutional Review Board, is a retrospective chart review comparing two dosing strategies of cyclosporine and tacrolimus.  The following data was collected: patient age, gender, ethnicity, initial dose of cyclosporine or tacrolimus, time to therapeutic drug levels, time to engraftment, change in bilirubin, and change in serum creatinine. All data was recorded without patient identifiers and maintained confidentially. Data will be divided into a low initial dosing group and a high initial dosing group and time to therapeutic drug levels will be compared. Descriptive statistics will be utilized to compare starting doses of calcineurin inhibitors and time to therapeutic drug levels.

Conclusion:  If correlation is shown, allogeneic stem cell transplant recipients may be able to reach therapeutic drug levels sooner and further prevent graft versus host disease which would decrease mortality and morbidity in this high risk population.  Assessment of this dosing protocol may lead to more aggressive and individualized dosing strategies.