Allergies
Maria G. Tanzi, PharmD
Incorporation of a pharmacist-led penicillin allergy skin testing (PAST) service into a community hospital’s antimicrobial program substantially improved the use of preferred antimicrobial therapies, according to data published in the June 15, 2021 issue of the American Journal of Heath-System Pharmacy (AJHP).
From October 2015 to December 2019, the pharmacist-managed service at Munson Medical Center in Traverse City, MI, screened 90 hospitalized patients with a remote history—more than 5 years prior to the current admission—of a penicillin reaction.
“The greatest impact has been a culture change in our institution in terms of the prescribing of preferred beta-lactams for our hospitalized patients with reported penicillin allergies,” said Nicholas Torney, PharmD, BCPS, BCIDP, an infectious disease clinical specialist at Munson Medical Center and author of the AJHP study with Michael Tiberg, PharmD, BCPS (AQ Infectious Diseases).
According to the study results, 76 of the 90 patients in the study safely transitioned to a preferred beta-lactam.
“Since our skin testing program has been in place for about 6 years now, we have observed providers becoming a lot more comfortable prescribing beta-lactams for appropriate patients,” Torney said. Prior to the PAST service, Torney and colleagues noted that vancomycin, cefepime, and metronidazole were the most commonly used antibiotics in patients who reported an allergy. However, after PAST, penicillin, piperacillin/tazobactam, and ampicillin/sulbactam were the most commonly used.
Getting started
Torney said there are steps pharmacists should consider before establishing a pharmacist-managed PAST service. It is important to first determine if the state allows it. He noted that the best way to find out is to contact the respective state board of pharmacy and inquire about what is needed if they do allow pharmacist-led PAST (e.g., an approved protocol by a pharmacy & therapeutics committee, a collaborative practice agreement, etc.).
Torney referred to an article published in February 2019 in AJHP by Bland and colleagues that includes information on PAST from 50 state boards of pharmacy. He said this is an excellent practical guide to help pharmacists get started with a PAST program.
Other considerations include buy-in from key stakeholders, such as infectious disease teams and pharmacy leadership, leveraging limited resources in a community hospital setting, and appropriate training. Torney said properly trained health care personnel is a must for PAST.
He relied on the Penicillin Allergy Assessment and Skin Testing Certificate Program to train clinicians. The program includes 11 hours of didactic webinars and 4 hours of live demonstration, and the requirement to perform 2 PASTs annually to maintain competency after the initial training.
Outpatient PAST services
Some outpatient initiatives have stemmed from the efforts that began in the inpatient setting, according to Torney.
The first intervention includes expanding PAST to pregnant patients in the community. This model asks a patient’s obstetrician/gynecologist to refer the patient to 1 of 2 local allergists in the community to perform PAST.
The results would then be available to the hospital, as select patients may need to be treated for group B streptococcus at the time of childbirth. Knowing if the patient can tolerate a beta-lactam in advance would help decrease the inappropriate use of other antibiotics.
The second intervention involves PAST being performed in the outpatient oncology infusion center by pharmacists for patients with a penicillin allergy who are scheduled to undergo an oncologic gynecologic surgery.
The proactive PAST in this outpatient setting allows the provider to determine if patients can tolerate beta-lactams, which may be needed for the patient once admitted for the procedure.
The current data show us that a pharmacist-managed/administered PAST service in a community teaching hospital is a viable tool to de-label penicillin allergies and optimize the use of preferred beta-lactam antimicrobial regimens.