The Impact of Penicillin Skin Testing on Aztreonam Stewardship and Cost Savings in Immunocompromised Cancer Patients.

OBJECTIVE: Reported penicillin allergies result in alternative antimicrobial use and are associated with worse outcomes and increased costs. Penicillin skin testing (PST) has recently been shown to be safe and effective in immunocompromised cancer patients, yet its impact on antimicrobial costs and aztreonam utilization has not been evaluated in this population. METHOD: From September 2017 to January 2018, we screened all admitted patients receiving aztreonam. Those with a self-reported history of possible immunoglobulin E (IgE)-mediated reaction to penicillin were eligible for PST with oral challenge. RESULTS: A total of 129 patients were screened, and 49 patients were included and underwent testing. Sixteen patients (33%) had hematologic malignancies and 33 patients (67%) had solid tumors. After PST with oral challenge, 46 patients (94%) tested negative, 1 patient tested positive on oral challenge, and 2 patients had indeterminate results. The median time from admission to testing was 2 days (interquartile range, 1-4). After testing negative, 33 patients (72%) were switched to beta-lactam therapy, which resulted in a total of 390 days of beta-lactam therapy. For identical therapy durations, the direct total antibiotic cost was $15 138.89 for beta-lactams versus $78 331.50 for aztreonam, resulting in $63 192.61 in projected savings. A significant reduction in median days of aztreonam therapy per 1000 patient days (10.0 vs 8.0; P = .005) was found during the intervention period. CONCLUSIONS: Use of PST in immunocompromised cancer patients receiving aztreonam resulted in improved aztreonam stewardship and significant cost savings. Our study demonstrates that PST with oral challenge should be considered in all cancer patients with reported penicillin allergies.

Safety, Efficacy, and Clinical Impact of Penicillin Skin Testing in Immunocompromised Cancer Patients.

BACKGROUND: Use of penicillin skin testing (PST) to rule out penicillin (PCN) allergies is safe and effective in immunocompetent patients; however, data on immunocompromised patients are limited. OBJECTIVE: We aimed to determine safety, efficacy, and clinical impact of PST in immunocompromised patients with cancer. METHODS: A quality improvement process establishing a PST service was implemented at MD Anderson Cancer Center. Adult patients admitted to leukemia and genitourinary medical oncology (GUMO) services with history of possible type I reactions to PCN were eligible for testing. RESULTS: Between April and October 2017, 218 patients with reported PCN allergies were screened; 100 met inclusion criteria and underwent PST (67 leukemia, 33 GUMO). The most common reported allergy was to PCN (64%), with 61% reporting cutaneous reactions and 79% reporting reactions more than 20 years ago. PST with oral challenge results were overwhelmingly negative (95%); only 4% tested positive, and 1 test result was indeterminate (negative histamine control). After negative PST and oral challenge results, 51% patients were transitioned to PCN-based antibiotics during the same hospitalization. During the follow-up period (median 177 days), 65 of 95 patients were readmitted (185 total readmissions), and 51 patients required antibiotic therapy, with 37 receiving a PCN-based antibiotic (accounting for 336 days of therapy). No patient who received PCN-based antibiotics experienced an immediate-type allergic reaction. CONCLUSIONS: Our findings support PST use in immunocompromised hosts. The widespread use of PST in patients with cancer will allow for optimal use of antimicrobial therapy and stewardship, which are vital in a population at increased risk for infections.

Multidisciplinary cancer care: development of an infectious diseases physician assistant workforce at a comprehensive cancer center.

The authors outline the process through which the infectious diseases department at The M. D. Anderson Cancer Center successfully integrated physician assistants into patient care services, as judged by an overall increase in departmental productivity, broadened patient care coverage, and physician satisfaction with midlevel services.