Tolerability of meropenem in children with IgE-mediated hypersensitivity to penicillins

Background: Administration of meropenem to penicillin-allergic patients who might benefit from this treatment is usually avoided because of a 47.4% rate of cross-reactivity to imipenem, the prototype of the carbapenem class of beta-lactam antibiotics, demonstrated in a single study on the basis of positive responses to skin tests with imipenem reagents. However, recent studies of ours have demonstrated a very low rate of cross-reactivity between penicillins and both meropenem and imipenem in adults. Objective: To assess cross-reactivity and tolerability of meropenem in children with documented penicillin allergy. Methods: One hundred and eight consecutive children who had suffered a total of 129 immediate reactions (120 urticarial and/or angioedematous manifestations and 9 anaphylactic shocks) to penicillins and had positive results to skin tests for at least one of the penicillin reagents tested underwent skin tests with meropenem and negative subjects were challenged with it. Results: One subject (0.9%) displayed a positive intradermal test to meropenem. The remaining 107 subjects with negative skin tests to meropenem tolerated challenges. Challenges were not followed by full therapeutic courses. Conclusions: Our results demonstrate a low rate of cross-reactivity between penicillins and meropenem. Therefore, the practice of avoiding meropenem in children with immunoglobulin E-mediated hypersensitivity could be abandoned; in those who especially require meropenem treatment, prophylactic skin tests are advisable, because negative results indicate tolerability.