Cefepime desensitization in a patient with cystic fibrosis

We report a case of successful parenteral desensitization to cefepime in a cystic fibrosis patient with multiple β-lactam sensitivities. A 36 year old male with cystic fibrosis experiencing a pulmonary exacerbation failed to improve on ciprofloxacin, linezolid and trimethoprim/sulfamethoxazole. He had a history of significant urticaria to penicillin, ceftazidime, aztreonam, and imipenem/cilastatin. Sputum culture revealed moderate growth of Pseudomonas aeruginosa and he was admitted to the intensive care unit for close vital sign observation during a cefepime desensitization procedure. Review of patient history confirmed that the patient was not receiving a beta-blocker drug. Epinephrine and diphenhydramine were available nearby if needed. Desensitization was achieved with 5 minute infusions of cefepime, starting from an initial dose of 0.032mg, followed by a 10 minute observation period. Doses were progressively doubled in a similar fashion at 15 minute intervals to a final dose of 2 grams which was given over 15 minutes. A novel electronic ordering protocol was used for serial dilution and administration instruction. Only three concentrations were mixed for infusion: 4mg/100ml, 100mg/50ml, and 2000mg/100ml; with adjustment of infusion rate to achieve appropriate dose with 16 total doses. After desensitization, the patient was able to tolerate scheduled infusions of cefepime at maximum dose without complications. Cefepime may be successfully administered to patients with a history of hypersensitivity reactions. It may be especially helpful in cystic fibrosis patients where multiple drug sensitivities are often prevalent.