A Proactive Approach to Penicillin Allergy Testing in Hospitalized Patients

Background Penicillin allergy testing is underutilized in inpatients despite its potential to immediately impact antibiotic treatment. Although most tested patients are able to tolerate penicillin, limited availability and awareness of this tool leads to the use of costly and harmful substitutes. Objective We established an inpatient service at a large academic hospital to identify and test patients with a history of penicillin allergy with the goals of removing inaccurate diagnoses, reducing the use of beta-lactam alternatives, and educating patients and clinicians about the procedure. Methods Eligible inpatients were flagged daily through the electronic medical record and prioritized via a specialized algorithm. A trained clinical pharmacist performed penicillin skin tests and challenges preemptively or by provider request. Clinical characteristics and antibiotic use were analyzed in tested patients. Results A total of 1203 applicable charts were detected by our system leading to 252 direct evaluations over 18 months. Overall, 228 subjects (90.5%) had their penicillin allergy removed. Of these, 223 were cleared via testing and 5 by discovery of prior penicillin tolerance. Among patients testing negative, 85 (38%) subsequently received beta-lactams, preventing 504 inpatient days and 648 outpatient days on alternative agents. Conclusions Penicillin allergy testing using a physician-pharmacist team model effectively removes reported allergies in hospitalized patients. The electronic medical record is a valuable asset for locating and stratifying individuals who benefit most from intervention. Proactive testing substantially reduces unnecessary inpatient and outpatient use of beta-lactam alternatives that may otherwise go unaddressed.