Characterizing Antibiotic Use in Hospitalized Patients With a Documented Penicillin Allergy

Patients with self-reported penicillin allergies frequently receive unnecessary broad-spectrum antibiotics, which are associated with poor outcomes for patients and healthcare systems. The objective of this study was to determine the significance of broad-spectrum antibiotic prescription among patients with a documented penicillin allergy.

Retrospective chart review identified a cohort of penicillin allergic patients admitted to the primary medical-surgical floors at Avera McKennan that received intravenous or oral antibiotics. We recorded the allergy manifestation and severity, and all antibiotics administered within 24 hours of admission. The cohort was further divided into various subgroups and analyzed using Chi-Square or a Fischer's exact test.

190 patients with documented penicillin allergies received antibiotics between Dec. 1, 2018, and March 31, 2019. A severe penicillin allergy was documented in 86.3 percent of cases. Cephalosporins, vancomycin, and fluoroquinolones represented 34.1 percent, 18.2 percent, and 12.7 percent of initial antibiotics, respectively. No significance was noted in the comparison of antibiotic choice between patients with a specified versus an unspecified penicillin allergy. The number of cephalosporin prescriptions was significantly lower in a surgical prophylaxis subgroup of patients compared to a non-surgical prophylaxis subgroup.

Our study supports literature suggesting patients with documented penicillin allergies are at risk of unwarranted broad-spectrum antibiotic use. We noted an alarming number of unverified penicillin allergies. Prescription patterns did not appear to be altered based on verification or type of recorded allergic reaction. Surgical patients may be at greater risk. Our findings call for heightened antibiotic stewardship especially regarding patients with a documented penicillin allergy.