Impact of the implementation of a pharmacist-driven immunosuppression drug monitoring protocol for hematopoietic stem cell transplant recipients

For patients with serious hematologic malignancies, hematopoietic stem cell transplantation (HSCT) is a potentially curative treatment option. Majority of HSCT recipients receive tacrolimus as part of their immunosuppressive regimen. The purpose of this study is to evaluate the clinical impact of a pharmacist driven immunosuppression drug monitoring protocol for HSCT recipients on tacrolimus. This was a single-center, pre-post interventional study conducted at the University of Chicago Medical Center. Data collected via chart review includes the immunosuppressive agent used, interacting medications, adverse events, dose adjustments, drug concentrations, time to engraftment, and diagnosis of GVHD. Following the incorporation of a therapeutic drug monitoring protocol, the percentage of therapeutic tacrolimus levels was similar to when there was no protocol in place; 68% versus 64%, respectively (p = 0.34). There were 18 total adverse events observed in the pre-protocol group versus 10 in the post-protocol group (p = 0.03). Nephrotoxicity was the most common adverse event occurring in 23% of patients in the pre-protocol group and 15% of patients in the post-protocol group (p = 0.18). In the post-protocol group, there were 20 patients with two or more interacting drugs versus two patients in the pre-protocol group (p < 0.05). Additionally, the post-protocol group had 12 instances of an empiric dose adjustment made whereas the pre-protocol group had three instances (p = 0.006). Although there was no significant difference in percentage of therapeutic tacrolimus levels, pharmacist involvement resulted in improved safety outcomes such as management of drug interactions and incidence of adverse events.