1793. Description of a Pharmacist-Managed Penicillin Allergy Skin Testing (PAST) Service at a Community Teaching Hospital

BACKGROUND: Penicillin allergies routinely result in the use of alternative antibiotics, which has shown to increase healthcare cost, length of stay, and the incidence of multi-drug-resistant organisms. The goal of this study was to describe how a pharmacist-managed PAST service could be incorporated into an antimicrobial stewardship program to optimize antimicrobial therapy in patients who report a penicillin allergy and require a penicillin antibiotic. METHODS: The core members trained to conduct a PAST were an Infectious Diseases (ID) physician, ID pharmacist, PGY2 ID pharmacy resident, and five PGY1 pharmacy practice residents. Patients were identified through ID physician consult and/or antimicrobial stewardship team rounds. Patients greater than 18 years old were considered for PAST if they had a history of a type 1, or unknown, allergic reaction to penicillin that occurred greater than 5 years ago and a β-lactam antibiotic was indicated. Patients were excluded for the following reasons: pregnancy, non-type 1 allergic reaction, and recent use of anti-histamines. The primary objective was to reduce the use of alternative antimicrobials such as carbapenems, vancomycin, and fluoroquinolones. Secondary objectives included tolerability of the PAST and β-lactam therapy, and days of alternative antibiotics avoided. RESULTS: Fifty-eight PASTs were initiated from October 2015 to April 2018. Fifty-six out of 58 (97%) patients completed a PAST. Of the 56 patients that completed a PAST, the negative predictive value was 100%. The most common antibiotics prior to PAST were vancomycin, cefepime, and fluoroquinolones. The most common antibiotics after PAST were penicillin, piperacillin/tazobactam, and amoxicillin/clavulanate. Bacteremia and skin and soft-tissue infection were the most common indication and Enterococcus and Streptococcus sp. were most frequently isolated. Of the 50 patients that were transitioned to a preferred β-lactam, the number of days of alternative antibiotics avoided ranged from 2 to 180, with a mean of 22.2 days and median of 11 days. CONCLUSION: Incorporating a pharmacist-managed PAST service into a community hospital’s antimicrobial stewardship program can improve the utilization of preferred antimicrobial therapy and avoid toxic, more costly antimicrobials. DISCLOSURES: N. Torney, ALK Abello, Inc.: Speaker’s Bureau, Speaker honorarium.