Evaluation of the Pharmacokinetic Interaction Between Letermovir and Tacrolimus in Allogeneic Hematopoietic Cell Transplantation Recipients.

Data describing the magnitude of the pharmacokinetic interaction between letermovir and tacrolimus in allogeneic hematopoietic cell transplantation (allo-HCT) recipients are limited, and varying outcomes have been reported. The need for empiric dose adjustment of tacrolimus on initiation of letermovir has not been established; instead, guidelines suggest closely monitoring the tacrolimus trough concentration and adjusting the dose as needed. A better understanding of this interaction is imperative to accurately manage the narrow therapeutic window of tacrolimus post-transplantation.