Background: B-lactam antibiotics, in particular penicillins, are the most commonly reported drug allergies in the United States; however, only 10% of patients are truly allergic when tested. Patients with a B-lactam reaction documented in their electronic health record more commonly receive excessively broad-spectrum antibiotics; not only are B-lactams commonly first-line therapy for various infections, alternative therapies carry their own toxicities, costs and increased risk of antimicrobial resistance. Inaccurate B-lactam allergy documentation has been shown to adversely affect health outcomes.
Methods: A retrospective chart review of meropenem, aztreonam & linezolid use over a 6-month period was conducted at a county medical center. These antibiotics were selected as they have been previously identified as common alternative therapies for patients carrying B-lactam antibiotic reactions within the institution. Analysis included antibiotic allergy documentation, therapeutic indication, & appropriateness of therapy. B-lactams were defined as penicillins, penicillin-derivatives, or cephalosporins; carbapenems were not included in this definition for the purpose of this review.
Results: A total of 296 encounters (257 unique patients) were reviewed. The most common indication for therapy was lower respiratory infection (24%). Of patients reviewed, 35% had a documented B-lactam reaction; however, the majority of reactions were ineffectively described. The most common reaction was rash (47%), followed by type I hypersensitivity (28%), unknown (12%), and intolerance (9%). Per reviewers assessment, 83 out of 296 cases (28%) received an aforementioned antibiotic due to history of B-lactam reaction.
Conclusion: Over one-third of patients receiving broad-spectrum antibiotics had a documented B-lactam allergy, however most were ineffectively described. Improved documentation may help distinguish true allergies from intolerances and reduce broad-spectrum antibiotic use.
A. Ahiskali, None
R. Zadroga, None