The efficacy and safety of oral levofloxacin therapy for overall infection prophylaxis in cancer patients with neutropenia in outpatient settings.

Abstract

e18681 Background: Patients undergoing chemotherapy treatment are at risk for bacterial infection during their period of neutropenia. However, not all neutropenic patients are at high risk for developing infection. The purpose of this study was to evaluate the efficacy and safety of prophylactic oral levofloxacin in high, intermediate, and low infection risk patients with cancer in the ambulatory care setting. Methods: This was a retrospective chart review of 100 cancer patients with high, intermediate, and low overall infection risk who were prescribed outpatient oral levofloxacin prophylaxis between October 2019 and July 2020. This quality improvement project included adults with a history of malignancy and presence of neutropenia who have received chemotherapy treatment and oral levofloxacin therapy for overall infection prophylaxis. The primary efficacy outcome was the rate of hospital admission due to febrile neutropenia. The primary safety outcome was the occurrence of side effects of levofloxacin therapy. Secondary outcomes evaluated the duration of levofloxacin therapy, the rate of fluoroquinolone resistance in positive bacterial cultures, progression to sepsis in hospitalized patients and the rate of death due to mult-idrug resistance including fluoroquinolones. Results: Hospital admission due to febrile neutropenia after a chemotherapy cycle occurred in 18% of patients prescribed levofloxacin. Among hospitalized patients due to febrile neutropenia, 2% had low to intermediate overall infection risk and 16% had high overall infection risk. The primary safety outcome occurred in 25% of patients. The incidence of QTc prolongation occurred in 8% of patients; dermatologic side effects occurred in 9% of patients; the rate of Clostridioides difficile infection was 6%, and the rate of tendon rupture was 2%. Median duration of levofloxacin prophylaxis in the low overall infection risk group was 7 days, compared to the intermediate overall infection risk group (8.5 days) and the high overall infection risk group (14 days) with Kruskal-Wallis test p-value of 0.0009. The rate of fluoroquinolone resistance in positive bacterial cultures was 10%. Progression to sepsis in hospitalized patients occurred in 17% of patients. The rate of death due to multi-drug resistance including fluoroquinolone was 2%. Conclusions: Our findings signify preserved efficacy of levofloxacin prophylaxis in the ambulatory setting. Our findings should be considered to develop rational strategies to reduce fluoroquinolone overprescribing or limit duration of levofloxacin prophylaxis. If patients present with solid tumors and experience neutropenia, the use of antibacterial prophylaxis is not recommended because in general, patients recover from neutropenia quickly.