Magnitude and Predictors of Antimicrobial Use-Related Drug Problems inGeriatric Inpatients: Evaluation of Pharmacist Interventions

Introduction: Infections remain a major cause of illness and death in older adults. Physiological changes, polypharmacy, and chronic conditions complicate antimicrobial therapy and increase the risk of drug problems. Pharmacist-led interventions improve prescribing, but evidence from the United Arab Emirates is limited. This study evaluated the magnitude and determinants of antimicrobial use-related drug problems and assessed clinical pharmacist interventions in hospitalized older adults with infections. Methods: A retrospective observational study was conducted from February to July 2022 at a 350-bed tertiary care academic hospital in the United Arab Emirates. Medical records of patients aged 60 years and older admitted with infections and treated with systemic antimicrobials were reviewed. Drug-related problems were classified using the Hepler and Strand framework. Results: Among 102 patients, 85 antimicrobial-related drug problems were identified, with half experiencing at least one. Common categories were drug-drug interactions (29%), unnecessary use (18%), and overdosing (14%). Cephalosporins (21%), penicillins (12%), and fluoroquinolones (12%) were the most frequently implicated classes. Clinical pharmacists made 79 recommendations; 95% were accepted, and 91% were implemented. Main interventions were drug omission (28%), substitution (25%), and dose modification (23%). Prior antimicrobial use, polypharmacy, and longer hospital stay predicted drug problems. Discussion: The high prevalence of antimicrobial use-related drug problems highlights the challenges of polypharmacy and prolonged hospitalization. Findings reinforce the feasibility and acceptance of pharmacist-led interventions, supporting their role in antimicrobial stewardship. Conclusion: Clinical pharmacists are integral to optimizing antimicrobial therapy and improving medication safety in older adults.