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

Abstract

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.

Drug allergy management in the elderly

“…Adverse consequences among patients carrying a drug allergy have been well documented especially for beta-lactam antibiotics [14]. In a study among US veterans, with a mean age of 70 years old, there were statistically less adverse drug events (2 vs 12%, P < 0.005) and ESBL organisms (1 vs 6%, P ¼ 0.06) using preferred compared with nonpreferred antibiotics [15].…”

Challenges and opportunities related to penicillin allergy in the Veterans Health Administration: a narrative review

“…Other VA single-site studies have also reported an association between β-lactam allergy (mainly to penicillin-class antibiotics) and suboptimal antibiotic choices both in the outpatient and inpatient settings. [17][18][19] However, no consistent adverse signal on The presence of a penicillin allergy was not associated with differences in the rates of surgical site infections, though it was associated with antibiotic selection. Only smoking and vancomycin monotherapy were found to be independent predictors of SSIs.…”

Editorial: Advances in drug hypersensitivity reactions

“…Most of the studies assess the response to cephalosporins and other beta-lactams in patients with proven sensitization to penicillins. It is well known that in subjects allergic to penicillins there are cases who are sensitized to the nucleus of the beta-lactam formed by the tetracarbonyl ring that confers the beta-lactam structure; however, in other cases, it is the side chain that is the main contributor to the epitope [10]. In theory this recognition is also made with cephalosporins and other beta-lactams, including monobactams like aztreonam [10,11].…”

“…They report antibiotics and nonsteroidal anti-inflammatory drugs to be the two commonest drug classes to cause hypersensitivity. De-labelling reported antibiotic reactions is particularly important in the elderly population due to the high risk of developing resistant organisms with nonpreferred antibiotics [10]. The presentation of hypersensitivity can be more varied and symptoms often unclear due to polypharmacy and underlying health issues.…”

“…It is well known that in subjects allergic to penicillins there are cases who are sensitized to the nucleus of the beta-lactam formed by the tetracarbonyl ring that confers the beta-lactam structure; however, in other cases, it is the side chain that is the main contributor to the epitope [10]. In theory this recognition is also made with cephalosporins and other beta-lactams, including monobactams like aztreonam [10,11]. When considering cross-reactivity the side chain is relevant and may contribute to cross-reactivity although this is far from absolute.…”