Penicillin allergy labels are associated with a greater number of courses of antibiotics after hospitalization.

Background: Patients with penicillin allergy have been shown to have suboptimal antibiotics prescribed for infections as well as an increased risk of adverse effects. However, it is currently unknown at what rate patients with penicillin allergy are prescribed antibiotics after hospitalization. Objective: The purpose of this study was to determine the rate at which patients with penicillin allergy are prescribed antibiotics after hospitalization and if this rate differs from that of patients without penicillin allergy. Methods: This was a retrospective case-control study that evaluated subsequent courses of antibiotics after hospitalization in patients with and those without penicillin allergies. Subsequent courses of antibiotics were compared between patients who with penicillin allergy and patients who were not allergic to penicillin for the 15 months after hospitalization by using the incidence rate ratio of new antibiotics prescribed. Results: Patients in the penicillin allergy group received significantly more outpatient antibiotics in the 15 months after hospitalization compared with patients with no penicillin allergy. The incidence rate ratio between the two groups was 1.27 (95% confidence interval, 1.10-1.48); p = 0.0014. There was no difference between the subsequent courses of inpatient antibiotic courses during the same time period. Conclusion: Patients with a penicillin allergy in the current evaluation received significantly more outpatient courses of antibiotics than did the patients without a penicillin allergy. These data provide more evidence for the importance of penicillin allergy de-labeling to provide patients with the most appropriate antibiotics for their respective infections.