Pharmacist‐led dosing reduces tacrolimus intrapatient variability in lung transplant recipients

Abstract

Intrapatient variability (IPV) of tacrolimus has become a marker for predicting transplant outcomes, though minimal data exists regarding strategies to improve tacrolimus IPV. Following the implementation of comprehensive outpatient clinical pharmacy services, the impact of a dedicated lung transplant pharmacist on 1-year tacrolimus variability and clinical outcomes in lung transplant recipients (LTRs) were investigated. A retrospective study of two LTR cohorts was conducted at a singlecenter institution. Cohort 1 included LTRs from January 1, 2015 to December 31, 2017 with tacrolimus dose adjustments made by physicians or nurse practitioners, and were seen by a pharmacist on an ad hoc basis. Cohort 2 included LTRs from January 1, 2018 to December 31, 2019 with tacrolimus adjustments made solely by a pharmacist who saw them at each routine visit with the multidisciplinary team for the first year post-transplant. The primary outcome assessed tacrolimus variability by the coefficient of variation 12 months post-transplant. Secondary outcomes assessed post-transplant hospital readmissions, acute cellular rejection (ACR), donor-specific antibodies (DSA), and mortality at 12 months post-transplant. No protocol changes occurred during the study period. Chi-squared and t-tests analyses were utilized. Sixty-three LTRs were included, 39 patients in Cohort 1 and 24 inCohort 2 with no significant differences between cohorts. At 1-year post-transplant, Cohort 2 had lower median tacrolimus variability (35.7% vs. 30.3%, p = 0.02) and more patients had a tacrolimus variability <30% (20.5% vs. 45.8%, p = 0.03). There were no differences in readmission rates, ACR, DSA, or mortality 12 months posttransplant. Based on this single-center limited cohort study, the integration of a dedicated ambulatory transplant pharmacist improved tacrolimus variability 1 year following lung transplant. Further studies are needed to assess long-term morbidity and mortality rates.