Solving the Drug Allergy Puzzle: A Q&A With Ami Belmont

Ami Belmont, MD, instructor of medicine (rheumatology, allergy and immunology), came to Yale School of Medicine for the Combined Internal Medicine/Pediatrics Residency Program (Med-Peds), then stayed on as chief resident with Yale Primary Care/Internal Medicine and then as an allergy and immunology fellow. Alongside her mentor, Jason Kwah, MD, MSc, she studies interventions related to drug allergy.

In a Q&A, Belmont discusses the impact of antibiotic allergy labels on patient care, the intervention she performed at Yale New Haven Health System, and the latest guidelines for caring for surgical patients with penicillin allergies.

I find that thinking through each patient case is like solving a puzzle in which you have to put different pieces of information together—the patient’s history, the medication, the testing—and then you make a decision. Oftentimes you can clear patients of these allergies and expand access to important first-line, or preferred, treatments.

During the pandemic, when I was involved in hospital operations that needed to be quickly changed and working to improve patient care and access, I became interested in large-scale interventions. I realized that large-scale interventions, as they relate to antibiotic allergy labels, could have big implications for patient care.

Many patients’ medical records have antibiotic allergy labels, or reported allergies to antibiotics. Ten to 15 percent of patients have a reported penicillin allergy. These patients are less likely to get preferred antibiotics. For example, for surgical patients, cefazolin is the preferred antibiotic to prevent surgical site infections. Cefazolin is effective and has low side effects. Patients who receive cefazolin are less likely to develop multi-drug resistant infections.

Because cefazolin is avoided in patients with penicillin allergy labels, these individuals commonly get alternative antibiotics that are broader spectrum and have more side effects. These patients have an increased chance of developing surgical site infections and multi-drug resistant infections, have longer hospital stays and increased health care costs, and even increased mortality.

But 95% of patients’ records are mislabeled, meaning these patients don’t actually have an allergy to penicillin, and they can tolerate the antibiotic. If we can de-label patients who don't have these allergies and expand access to first-line treatments—the treatment that works best—we can improve patient outcomes.

We performed a multidisciplinary intervention at Yale New Haven Health System to improve utilization of first-line prophylactic antibiotics for surgical site infections. Our study demonstrated that implementing a guideline and best practice advisory alert for surgical patients with reported penicillin allergy to receive cefazolin was safe and effective. We now know that patients with penicillin allergy are at no higher risk of reaction when given cefazolin than anyone else. That’s a newer understanding, and national surgical guidelines haven’t yet caught up yet. Our intervention changed the Yale New Haven Health guidelines to use cefazolin for surgical prophylaxis for patients with reported penicillin allergy.

Based on our numbers, 11% of patients who undergo surgeries at Yale have penicillin allergy labels. Already we are impacting thousands of patients a year at Yale New Haven Hospital alone by ensuring they can get first line surgical prophylaxis. We’re preventing surgical site infections and adverse effects from the alternative antibiotics.

Our study is the largest to date looking at an intervention to expand the use of cefazolin for surgical patients with penicillin allergies. Not only did we demonstrate that our intervention was effective, but we also showed it was safe. Our hope is that this will change national and international guidelines on how to address surgical patients with penicillin allergies.

Yale School of Medicine’s Department of Internal Medicine Section of Rheumatology, Allergy and Immunology is dedicated to providing care for patients with rheumatic, allergic and immunologic disorders; educating future generations of thought leaders in the field; and conducting research into fundamental questions of autoimmunity and immunology. To learn more, visit Rheumatology, Allergy & Immunology.