Implementation of a penicillin allergy screening tool to optimize aztreonam use

The implementation of a penicillin allergy screening tool to optimize the use of aztreonam is described.

This study was conducted at a 528-bed tertiary referral community teaching facility and compared the use of aztreonam in patients before and after the implementation of a multipronged intervention consisting of a penicillin allergy screening tool (PAST), education, order set decision support, and prospective review of aztreonam orders by the antimicrobial stewardship team and clinical pharmacists. Patients for whom aztreonam was prescribed at any time during their presentation to the hospital January 1-June 30, 2013 (preintervention period), and September 1, 2013-February 28, 2014 (postintervention period) were eligible for inclusion. Primary outcomes included total and inappropriate aztreonam usage. Secondary outcomes included cost avoidance and safety.

A total of 496 aztreonam orders were reviewed. The total number of days of therapy (DOT) with aztreonam significantly decreased from 9.5 per 1,000 patient-days in the preintervention group to 4.4 per 1,000 patient-days in the postintervention group (p < 0.0001). The number of inappropriate aztreonam DOT decreased from 4.0 per 1,000 patient days to 0.8 per 1,000 patient-days (p < 0.0001). The median number of inappropriate aztreonam doses decreased significantly in the postintervention period, as did inappropriate aztreonam DOT (p < 0.0001 for both comparisons). An estimated cost avoidance of $60,000-$100,000 was realized, depending on the alternative antibiotic selected.

Implementation of the PAST and provider and pharmacist education reduced the use of aztreonam by promoting the first-line use of β-lactam alternatives.