Implementation and Impact of a β -Lactam Allergy Assessment Protocol in a Veteran Population
Background: Approximately 10% of the US population reports having a β -lactam allergy, although nearly 90% do not have a true immunoglobulin E (IgE)-mediated reaction. This misconception results in using nonpreferred antibiotics, leading to antimicrobial resistance and treatment failure. To evaluate, clarify, and clear β -lactam allergies, we implemented a pharmacist-driven β -lactam allergy assessment (BLAA) protocol and penicillin allergy clinic (PAC). The purpose of this study was to illustrate the BLAA process, including the pharmacist-run PAC, and assess the impact on allergy clearance.
Methods: Clinical pharmacy specialists (CPS) evaluated hospitalized veterans with β -lactam allergies, using the BLAA protocol. Eligible patients could later be seen in PAC. This was a retrospective observational review of the BLAA protocol to assess recommendations for β -lactam antibiotic use and PAC outcomes.
Results: Between November 2017 and February 2020, 278 patients were evaluated, and 32 were seen in the clinic. The most common allergen was penicillin, and the most reported reaction was a rash (27%) or pruritus and urticaria (18%). Through PAC and the BLAA protocol, 86 patients (31%) were cleared for allergy removal, and 188 (68%) were cleared for alternative β -lactams. The evaluation revealed that 274 patients (99%) were eligible to receive a β -lactam antibiotic, and only 4 patients (1%) were recommended for avoidance of all β -lactams.
Conclusions: These findings highlight the utility of the pharmacist-driven BLAA protocol. We illustrated that most patients with documented β -lactam allergies were eligible for alternative β -lactams. The implementation of the BLAA protocol and pharmacist-run PAC facilitated allergy clearance and has the potential to promote alternative β -lactam use.
Accounting for those patients who have not been seen in PAC, our results are in concordance with previous studies, which demonstrated that implementation of a similar BLAA process results in clearance of ≥ 90% of penicillin allergies.13-17Other studies have evaluated inpatient implementation of penicillin skin testing or oral challenges; in this study, however, BLAAs were completed while the patient was hospitalized, and patients were seen in PAC after discharge. Completing BLAA during hospitalization not only allows for faster assessment and facilitates decision making regarding most patients’ antibiotic regimens, but also provides a tool that can be used by many pharmacists and HCPs. The addition of our PAC to the BLAA protocol further strengthens the impact on clearance of patients’ penicillin allergies.
Limitations
Although our study demonstrates many benefits of implementation of a BLAA protocol and PAC, it has several limitations. This analysis was a retrospective review of the limited number of patients who had assessments completed. Additionally, many patients were waiting to be seen in PAC. This delay is largely due to the length of time to establish our pharmacist-run PAC, the limited number of pharmacists trained and available for skin testing, the time constraints of our staff, and COVID-19 pandemic. Additionally, only pharmacists administer the BLAA questionnaire, but this process could be expanded to other professionals such as nursing staff. Also, this study was not set up as a before-and-after analysis that examined outcomes associated with individual patients. Future directions include assessing the clinical impact of this protocol, such as evaluating provider utilization of β-lactam antibiotics for patients with penicillin allergies and determining associated cost savings.
Conclusions
This study demonstrated that implementation of a pharmacist-driven BLAA protocol and PAC can effectively remove inaccurate penicillin allergy labels and clear patients for alternative β-lactam antibiotic use. The BLAA process in conjunction with PAC will continue to be used to better evaluate, clarify, and clear patient allergies to optimize their care.
