When patients with cancer need antibiotic treatment, a penicillin allergy can complicate the process and result in the use of more expensive, second-line antibiotics that tend to be less effective and potentially more toxic. Penicillin allergy testing (PAT) protocols have not always been available to patients with malignancies, often out of fear of increased risk of neutropenia.

A team of researchers found that appropriate testing could remove the “allergic” label from many of those patients’ records and allow them to be eligible for penicillin and its derivatives. Their study results were published in the Clinical Journal of Oncology Nursing.

The researchers developed and implemented an oncology outpatient nurse-driven PAT program at Memorial Sloan Kettering Cancer Center in New York, New York. Their testing began in an outpatient infusion unit, where nurses have the training and expertise to manage hypersensitivities and reactions. The nurses also were prepared to work with each patient on a 1:1 ratio throughout the entire PAT process.

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The PAT program comprised 3 steps. The first step was a scratch test involving 4 components: benzylpenicilloyl polylysine injection (PRE-PEN®), penicillin G potassium injection (10,000 units/mL), histamine base (1 mg/mL for positive control), and normal saline (for negative control). If a patient tested negative, they moved on to the second step.

The second step was an intradermal test using all of the same components except histamine. Again, if the patient tested negative, they moved on to the next step — in this case, the third and final step: the IV challenge dose. During this final step, a nurse oversaw the administration of 10% of the volume of antibiotic at a regular rate. A final negative reaction resulted in the removal of that drug allergy from the patient’s chart.

Overall, the team screened 82 outpatients who reported having a penicillin allergy. Of those, 74 patients went on to PAT, and 72 completed all 3 testing levels and tested negative for a penicillin allergy.

“There was a significant decrease in aztreonam use in patients with a hematologic malignancy who underwent [hematopoietic stem cell transplantation] (P <.05) one year after the initiation of PAT (start date November 26, 2018) as compared to patients who had a hematologic malignancy and underwent HCST one year before PAT was started [17 of 46, or 37% vs 9 of 52, or 17%],” the researchers concluded.  This also resulted in a drug cost savings of nearly $25,000.  

The researchers noted that the study was partly limited because of constraints on resources, and they could not offer PAT to all patient populations at implementation. But they also noted that the initiative demonstrated the importance of the role that nurses can play in PAT, including PAT in the outpatient setting. It is also another example of the contributions that nurses can make to the areas of antibiotic stewardship and improved patient care.


Morjaria S, Inumerables F, Patel D, et al. Penicillin allergy testing: an outpatient nurse-driven program for patients with cancer. Clin J Oncol Nurs. 2021;25(2):143-150. doi:10.1188/21.CJON.143-150