The ICU pharmacist's contribution to antimicrobial optimization through routine pharmacist interventions

Antimicrobials are among the medication groups most frequently involved in medication errors and adverse drug events in the Intensive Care Unit (ICU). Despite growing evidence supporting the role of Critical Care Pharmacists (CCPs) in antimicrobial stewardship, their integration into ICU teams remains inconsistent across European healthcare systems.

A prospective observational study was conducted over five months in an 18-bed medical-surgical ICU at a tertiary-level hospital in Spain. All admitted patients were included. A specialist pharmacist reviewed daily antimicrobial prescriptions through the electronic prescribing system. Pharmaceutical interventions (PIs) were classified as proactive or reactive and categorised by intervention type according to a predefined taxonomy. A descriptive analysis was performed.

A total of 331 PIs were recorded, of which 150 (45.31%) corresponded to antimicrobial therapy, representing the most frequently involved medication group. This figure corresponds to a mean of 1.50 antimicrobial-related PIs per working day. Of these, 115 (76.67%) were proactive. The most frequent intervention type was dose adjustment for overdosing or excessive duration (47.33%), followed by dose adjustment for underdosing or insufficient duration (18.00%), therapeutic drug monitoring recommendations (10.67%), and drug information to clinical staff (6.66%).

CCPs identify a substantial number of antimicrobial-related drug problems in the ICU through routine prospective review. The coexistence of overdosing and underdosing interventions reflects the pharmacokinetic complexity of this population. These findings support the formal integration of CCPs into ICU antimicrobial stewardship activities.