Typing safe antibiotics in amoxicillin hypersensitive patients--development of a stepwise protocol.

Introduction: A history of an adverse reaction to amoxicillin, irrespective of the mechanism involved, significantly elevates patients’ anxiety and affects therapeutic decisions in the future, leading to unnecessary avoidance of antibiotics. As a consequence, it would be useful to find a safe and reliable protocol for typing safe alternative antibiotics. The aim of the study was to determine negative predictive value of typing safe antibiotic in patients with a history of hypersensitivity reaction to amoxicillin. Material and methods: 71 patients, aged 20−83, with a history of an adverse reaction to amoxicillin were retrospectively analysed. On the basis of the reaction type they were divided into three groups: A — symptoms not typical for hypersensitivity reactions, B — allergy manifested by urticaria and/or angioedema, C — anaphylaxis. In group A amoxicillin was tested, in group B — cefuroxime, and in group C — macrolide: azithromycin or clarithromycin. Telephone follow-up visits were performed twice: 6−12 months and 3−5 years after the clinical assessment to evaluate tolerance of antibiotics. On the basis of the follow-up results, the negative predictive value (NPV) of the protocol was calculated. Results: The full diagnostic protocol was applied in 62 participants. Amoxicillin was found safe in 22, cefuroxime — in 21 and macrolide — in 19 patients. No anaphylactic reactions were observed during the tests. On the basis of the telephone follow-up, the NPV of the protocol was 96% in the first follow-up and 97% in the second one. Conclusion: A stepwise approach including SPTs, ICTs and provocations with amoxicillin / cefuroxime/macrolide — depending on a patient’s history — is safe and allows typing an antibiotic in the vast majority of patients.