Background: Local antimicrobial susceptibility patterns should be considered for antimicrobial therapy decisions. Antibiogram data can guide beta-lactam antibiotic use in the presence of a penicillin allergy, particularly when allergic cross-reactivity among antibiotic agents is unlikely.
Objective: To evaluate the effect of a multidimensional antimicrobial stewardship intervention to improve antibiogram-driven antibiotic selection for patients with a reported penicillin allergy receiving aztreonam.
Methods: This historically controlled, quasi-experimental study compared historical aztreonam use with prospective antibiotic selection following a pharmacist-led intervention in patients with a penicillin allergy. The impact of this intervention on aztreonam use, antimicrobial selection, patient allergy profile updates, length of stay, in-hospital mortality, and antibiotic cost savings was assessed.
Results: A significant reduction in median days of aztreonam therapy (4.0 vs. 2.0; p = 0.0001) and median days of therapy per 1000 patient days (14.5 vs. 9.3; p = 0.0001) was found in the intervention group.
Conclusion: A pharmacist-led antimicrobial stewardship intervention facilitated antibiogram-driven antibiotic therapy while reducing aztreonam use in patients without an anaphylactic penicillin allergy. Further trials are needed to assess the utility of similar antimicrobial stewardship interventions for patients with penicillin allergy.
Keywords: Antibiogram; Antibiotic resistance; Antimicrobial stewardship; Beta-lactam antibiotics; Drug allergy; Infectious diseases; Medical education.