Prophylactic Levofloxacin Use in Oncology and Hematopoietic Stem Cell Transplants for Children Under 2 Years of Age

Area of Science:

• Pediatric Oncology
• Infectious Diseases
• Pharmacology

Background:

• Levofloxacin (LVX) is used for prophylaxis in pediatric patients with hematologic malignancies or after hematopoietic stem cell transplantation (HSCT).
• Limited data exists on LVX efficacy and safety in infants under 6 months compared to older children in these high-risk groups.

Purpose of the Study:

• To evaluate the efficacy and safety of levofloxacin prophylaxis in infants under 6 months compared to older children (6 months to 2 years) undergoing treatment for acute myeloid leukemia (AML), relapsed acute lymphoblastic leukemia (rALL), infant ALL (iALL), Down syndrome with ALL (DS ALL), or HSCT.

Main Methods:

• A retrospective chart review was conducted at Children's Mercy Hospital from April 2019 to September 2024.
• Data from 79 patient encounters receiving LVX prophylaxis were analyzed for bacteremia, febrile neutropenia, and adverse drug reactions.
• Statistical analysis compared outcomes between infants under 6 months and older children.

Main Results:

• Bacteremia occurred in 9% of encounters, with no significant difference between the age groups (P=0.643).
• While some secondary outcomes like antibiotic exposure duration and liver enzyme elevations differed, clinical significance was limited by baseline differences.
• No differences were observed in febrile neutropenia, total LVX exposure, or time to first fever.
• One isolate of Streptococcus mitis showed resistance to LVX.

Conclusions:

• This preliminary study suggests comparable efficacy of LVX prophylaxis against bacteremia in young infants and older children with hematologic conditions.
• Further research with larger cohorts is necessary to confirm these findings and assess long-term safety in vulnerable pediatric populations.
• The emergence of LVX resistance in one isolate warrants ongoing surveillance.