Successful meropenem desensitization in a patient with cystic fibrosis

To report a case of successful meropenem desensitization in a patient with cystic fibrosis (CF) with documented hypersensitivity to multiple antibiotics including carbapenems.

A 20-year-old white man with CF was admitted to the hospital for treatment of an acute pulmonary exacerbation caused by multidrug-resistant Burkholderia cepacia complex and methicillin-resistant Staphylococcus aureus (MRSA). Past treatments of his CF exacerbations were complicated by urticarial eruptions following administration of beta-lactams, including meropenem, and ototoxicity from aminoglycosides. Skin testing revealed hypersensitivity reactions to beta-lactam antibiotics including penicillin, piperacillin/tazobactam, ceftazidime, and imipenem. A literature review (MEDLINE, January 3, 2002) and communication with the manufacturer of meropenem revealed no specific information on desensitizing patients to this agent. Because of meropenem's activity against B. cepacia complex alone and in combination with other antimicrobials, a desensitization protocol was adapted and applied to meropenem in an effort to provide the most beneficial treatment available. A 12-dose escalation protocol was successfully employed without incident.

Antimicrobial therapy is limited in CF patients by susceptibility profiles of common infecting organisms (e.g., Pseudomonas spp., B. cepacia complex, MRSA). Unfortunately, host responses may further reduce the utility of many effective antibiotic classes due to hypersensitivity and/or adverse reactions. Desensitization is a useful alternative that allows the administration of beneficial medications to patients with documented allergy histories.

Meropenem is an important treatment option in the CF population, particularly due to its activity against B. cepacia complex. Successful desensitization using a dose-escalation protocol in patients with a documented carbapenem allergy will allow the most beneficial therapy to continue.