Value Based Project to Evaluate the Incidence and Management of Antibiotic Allergies in Hematopoietic Cell Transplantation Recipients

Antibiotic use is an important supportive care measure during hematopoietic cell transplantation (HCT). At our institution, piperacillin/tazobactam is the preferred first line agent for neutropenic fever. In this setting, patients who report a penicillin allergy receive more costly antibiotics whose efficacy has not been proven in clinical trials. As part of an institutional effort to improve the value of HCT by decreasing costs and enhancing patient outcomes, we initiated a project to review the incidence of antibiotic allergies pre-transplantation, to evaluate the need and feasibility of allergy testing, and to establish a process for allergy testing in patients with a history of penicillin allergy. We retrospectively reviewed patient reported allergy history in 191 consecutive adult patients who received an autologous or allogeneic HCT at our institution in 2014. We collected their antibiotic allergies, including the reaction (if noted), that was documented prior to the transplant admission. The median age at HCT was 55 years (range 21-77 years). Transplant types were: autologous 111 (58%); reduced-intensity allogeneic 36 (19%); and myeloablative allogeneic 44 (23%). Of these patients, 27 (14.1%) reported an allergy to penicillin. Reported reactions were: rash (55.6%); unknown (22.2%); itching (18.5%); hives (11.1%); swelling (7.4%); and anaphylaxis (3.7%). More than one reaction could have been reported. Additionally, 29 patients (15.2%) reported an allergy to another antibiotic: sulfa (7.3%); cephalosporin (4.7%); carbapenem (0.5%); fluoroquinolone (1.6%); tetracycline (2.1%); vancomycin (0.5%); macrolide (1%); daptomycin (0.5%); and clindamycin (0.5%). This review revealed that almost 1 in 5 of our patients reported an allergy to penicillin or cephalosporin antibiotics, which predisposes them to the use of alternative antibiotics during their transplant admission that may be more expensive, less efficacious/safe, and associated with greater nosocomial rates of resistant enterococci and staphylococcus strains. Based on these data, we have established a process in collaboration with our Allergy and Clinical Immunology department where patients reporting penicillin allergy are referred for skin testing and, if indicated, desensitization during the pre-BMT workup period. We anticipate this will lead to a cost-effective approach to antimicrobial therapy in HCT recipients and will increase the use of agents supported by published evidence while avoiding the use of more expensive antibiotics.