I evaluated a 67 year-old woman with multiple antibiotic sensitivities and recurrent pseudomonas skin infections. She has a history of anaphylaxis to penicillin (severe) in addition to multiple other sensitivities. The pseudomonas is sensitive to imipenem and meropenem. I did a search and could not find a reference in which non-irritating concentrations of those antibiotics were evaluated. Is there any information available on the non-irritating concentrations of imipenem and/or meropenem for intradermal testing?


Thank you for your inquiry.

The abstracts copied below are of articles that will supply you with skin test protocols for both drugs.

Thank you again for your inquiry.

J Allergy Clin Immunol. 1988 Aug;82(2):213-7.
Imipenem cross-reactivity with penicillin in humans.
Saxon A, Adelman DC, Patel A, Hajdu R, Calandra GB.
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Department of Medicine, University of California-Los Angeles School of Medicine 90024-1680.
We examined the potential for IgE-mediated cross-reactivity between the carbapenems, a new class of beta-lactam antibiotics, represented by imipenem, and penicillins. In vivo skin testing with the relevant imipenem and penicillin determinants was undertaken. Having determined the concentrations of imipenem materials that did not induce false positive skin tests in nonpenicillin-allergic control subjects, we tested 40 subjects with a history of penicillin-allergic reactions. Twenty of these subjects were found to be nonallergic to penicillin on skin testing, and none of these subjects reacted to the imipenem determinants. In contrast, half the 20 subjects who were positive to one or more penicillin determinants also reacted to imipenem reagents. There was a good correlation between the penicillin and imipenem reagents to which the patients reacted. Imipenem should only be administered to penicillin-allergic subjects with similar precautions of penicillin administration to such patients.

Allergy. 2008 Feb;63(2):237-40. doi: 10.1111/j.1398-9995.2007.01532.x.
Tolerability of meropenem in children with IgE-mediated hypersensitivity to penicillins.
Atanasković-Marković M, Gaeta F, Medjo B, Viola M, Nestorović B, Romano A.
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Department of Allergology and Pulmonology, University Children's Hospital, Belgrade, Serbia.
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.

Phil Lieberman, M.D.

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