Impact of ß-Lactam Allergies on Antimicrobial Selection in an Outpatient Setting.

OBJECTIVE: The primary objective of this study was to determine whether patients prescribed nonpreferred antibiotics received appropriate alternative antibiotics. METHODS: This was a retrospective observational analysis of military veteran patients with a ß-lactam allergy treated in an outpatient clinic or emergency department for an infection during a 5-year span. Antibiotic regimens were first stratified as preferred or nonpreferred based on infection-specific guidelines. The nonpreferred regimens were then evaluated for appropriateness based on allergy history and culture and sensitivity reports. RESULTS: Of 445 fills of antibiotics evaluated, 269 met inclusion criteria, comprising 253 unique infections in 80 patients. Patients received nonpreferred antibiotics for their infection type in 57% of cases. Of the nonpreferred antibiotics, 56% were inappropriate based on guideline-recommended alternatives, allergy history, and culture and sensitivity data. Of the 88 allergies, 97% were historical/self-reported and 48% were cutaneous. In addition, 39% of patients safely received ß-lactam antibiotics after documentation of their allergy. CONCLUSIONS: Patients with documented ß-lactam allergies are at high risk of receiving nonpreferred and inappropriate antibiotics, and many reactions likely do not reflect true allergies. These data emphasize the negative impact of the "ß-lactam allergy" label and the importance of reassessing allergies.

Impact of Beta-Lactam Allergies on Selection of Antimicrobials in an Inpatient Setting Among Veteran Population.

PURPOSE: Beta-lactam antibiotics are among the most common and widely used antibiotics. However, reported allergy to this class of antibiotics is also common, leading to the use of alternative broad-spectrum antibiotics by healthcare providers. This has led to the emergence of various negative health outcomes. The purpose of the study is to investigate the impact of using alternative antibiotics secondary to a beta-lactam allergy among U.S. veterans who have otherwise multiple comorbidities. METHODS: This retrospective observational analysis was conducted over a 5-year period (January 1, 2011 to December 31, 2016) at the Memphis Veterans Affairs Medical Center (VAMC). Admitted patients with a documented beta-lactam allergy were categorized to preferred or non-preferred status based on initial antibiotic therapy antibiotic, allergy history, published guidelines, and local antibiogram. Preferred therapy was defined as the optimal antibiotic treatment for a given indication based on patient allergy history, published Infectious Disease Society of America guidelines, and local antibiogram of Memphis VAMC. The therapy was classified as "non-preferred" if it did not satisfy the preferred therapy criteria. Non-preferred treatments were further assessed for appropriateness based on indication and patient-specific factors. Chi-square and Fisher's exact tests were conducted to find a difference in rates of negative sequelae among patients receiving preferred vs. non-preferred treatments and appropriate vs. inappropriate treatments. FINDINGS: Of the 1806 admissions identified, data were collected on 95 unique patients with 147 different antibiotic regimens. There were 68 (52%) preferred treatment regimens and 64 (48%) non-preferred treatment regimens. Of the 64 non-preferred treatments, 43 (67%) were inappropriate. There was a statistically significant decrease in the number of adverse drug events and in the combined negative sequelae outcome among patients receiving preferred therapy vs. non-preferred therapy (2 vs. 12; P < .01 and 11 vs. 23; P < .01, respectively). IMPLICATIONS: The receipt of non-preferred antibiotic therapy among veterans with a recorded beta-lactam allergy may be associated with an increased risk of developing negative outcomes. Among military personnel, removing unnecessary beta-lactam allergies would improve readiness with optimal antibiotic choices and avoidance of unnecessary risks, expediting return to full duty.

Implementation and Impact of a ß-Lactam Allergy Assessment Protocol in a Veteran Population.

BACKGROUND: Approximately 10% of the US population reports having a ß-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 ß-lactam allergies, we implemented a pharmacist-driven ß-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 ß-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 ß-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 ß-lactams. The evaluation revealed that 274 patients (99%) were eligible to receive a ß-lactam antibiotic, and only 4 patients (1%) were recommended for avoidance of all ß-lactams. CONCLUSIONS: These findings highlight the utility of the pharmacist-driven BLAA protocol. We illustrated that most patients with documented ß-lactam allergies were eligible for alternative ß-lactams. The implementation of the BLAA protocol and pharmacist-run PAC facilitated allergy clearance and has the potential to promote alternative ß-lactam use.