Impact of a Standardized Beta-Lactam Allergy Questionnaire on Aztreonam Use

This quasi-experimental study compared the aztreonam utilization in patients with self-reported beta-lactam allergies admitted to an inpatient service between two study periods (pre- and post-implementation). Post-implementation followed the initiation of a standardized beta-lactam allergy questionnaire, a student pharmacist-driven performance improvement project for beta-lactam allergy documentation. Interviews clarified the allergy, reaction history, and any previous tolerance of beta-lactams. If receiving aztreonam at the time of the questionnaire, recommendations were made for changes in therapy if deemed appropriate by the pharmacist.

A total of 95 patients were included in the pre-implementation group versus 65 patients in the post-implementation group. Baseline characteristics were similar. The average number of aztreonam doses per 1000 patient-days in the post-implementation group was decreased (21.23 vs 9.05, P = .003). The average number of days of therapy per 1000 patient-days in the post-implementation group was decreased (8.79-4.24, P = .016). An increase in the number of aztreonam de-escalations was observed post-implementation (P = .003). A total of 122 questionnaires were completed with 114 allergy documentation updates. There were no reported instances of adverse events.

Utilization of a standardized beta-lactam allergy questionnaire as a pharmacy education tool resulted in a statistically significant decrease in aztreonam utilization, based on doses, days of therapy, and de-escalations.