Impact of a newly established expert clinical pharmacological advice program based on TDM results in tailoring antimicrobial therapies hospital-wide in a tertiary university hospital: findings after the first-year of implementation

Background: Therapeutic drug monitoring (TDM) may be helpful in tailoring treatment with antimicrobials, and expert interpretation of the results may make it more clinically useful. Method: The study aim was to assess retrospectively the first-year impact (July 2021-June 2022) of a newly established expert clinical pharmacological advice program (ECPA) based on TDM results in tailoring therapy with 18 antimicrobials hospital-wide in a tertiary university hospital. All patients having ≥1 ECPA were grouped in five cohorts [hematology, intensive care unit (ICU), pediatrics, medical- and surgical- wards]. Four indicators of performance were identified [total ECPAs; total ECPA recommending dosing adjustments/total ECPAs both at first and at subsequent assessments; turnaround time (TAT) of ECPAs, defined as optimal (<12h), quasi-optimal (12-24h), acceptable (24-48h), suboptimal (>48h)]. Results: A total of 8484 ECPAs were provided for tailoring treatment in 2961 patients, mostly admitted in the ICU (33.8%) and in the medical wards (29.4%). The proportions of ECPAs recommending dosing adjustments were >40% at first assessment (40.9% in hematology; 62.8% in ICU; 53.9% in pediatrics; 59.1% in medical wards; 59.7% in surgical wards), and decreased consistently at subsequent TDM assessments (20.7% in hematology; 40.6% in ICU; 37.4% in pediatrics; 32.9% in medical wards; 29.2% in surgical wards). The overall median TAT of the ECPAs was optimal (8.11h). Conclusions: The TDM-guided ECPA program was successful in tailoring treatment with a wide panel of antimicrobials hospital-wide. Expert interpretation by MD clinical pharmacologists, short TATs and strict interaction with ID consultants and clinicians were crucial in attaining this.