Delabeling Antibiotic Allergy in the Solid Organ Transplant Population Using a Multiple Antibiotic Allergy Evaluation Strategy.

Background: First-line antibiotics, such as penicillins, cephalosporins, and sulfonamides, are critical for preventing infections in immunocompromised solid organ transplant (SOT) patients. However, many patients are labeled with multiple antibiotic allergies (AALs) prior to transplant, increasing their risk of adverse outcomes. Because these patients often travel long distances and follow complex care plans, minimizing the number of drug allergy clinic (DAC) visits is important to avoid disruption and improve care continuity.

Methods: We conducted a retrospective cohort study of SOT patients evaluated at Vanderbilt University Medical Center outpatient DAC between 2014 and 2024. We assessed the efficacy, feasibility, and efficiency of a multiple antibiotic allergy evaluation strategy (MAAES), where patients with two or more low-risk AALs underwent consolidated evaluation, testing, and oral challenges, with the goal of delabeling as many as three AALs in a single visit.

Results: Among 184 SOT patients referred for evaluation, the median age was 57 years (IQR 47, 64); 112/184 (61%) were female, and 64/184 (35%) traveled from out-of-state. A total of 53 patients (29%) had two or more first-line AALs. Of these, 49 (93%) had labels successfully removed during their visit: 37 penicillin, 25 cephalosporin, and 24 sulfa allergy labels were delabeled. MAAES reduced the number of required visits to address these AALs by 61%.

Conclusions: MAAES enabled safe, efficient, and consolidated AAL evaluation and removal in SOT patients. In 57% of patients with ≥ 2 first-line AALs, all were safely delabeled in a single clinic visit, improving care efficiency and antibiotic access.