Levaquin Gets a Pass

Abstract

Antibiotic-induced gut dysbiosis has been associated with poor outcomes after intensive therapy. We evaluated the effect of levofloxacin (LEVO), the most commonly used prophylactic antibacterial antibiotic during intensive chemotherapy and allogeneic hematopoietic cell transplantation (allo-HCT), on the gut microbiota in 2 cohorts of patients, 1 cohort comprising 20 patients with acute leukemia receiving intensive chemotherapy and the other cohort comprising 20 allo-HCT recipients. 16S rRNA gene sequencing of thrice-weekly collected stool samples permitted a comparison between intervals with no antibacterial antibiotic exposure and those with only LEVO exposure. In mixed-effects modeling, the only variables influenced by LEVO were the relative abundances of Parabacteroides (regression coefficient, -.063; 99% confidence interval [CI], -.102 to -.024) and Blautia (regression coefficient, .050; 99% CI, .004 to .095). Other taxa and microbiota diversity were unaffected. Overall, the effect of LEVO on the gut microbiota in these cohorts was mild.

Effects of antimicrobial therapy duration and class on risk of antimicrobial‐resistant Gram‐negative bacillus bloodstream infection in patients with AML

“…While this finding may be in part be explained by the exclusion of isolated fluoroquinolone resistance from our definition of ARGNB, some studies do suggest that fluoroquinolones have a mild impact on gut microbiome diversity which may limit colonization with ARGNB and thus infection with these pathogens. 25,26 The risk of infection due to ARGNB is multifactorial and thus the impact of antimicrobial exposure on that risk cannot be understood without examining the context in which these agents were administered. Indeed, we found several other important predictors of ARGNB BSI in this study.…”

“…Reassuringly, we did not find an association between exposure to fluoroquinolones, which are frequently used as prophylaxis in neutropenic AML patients, and increased odds of ARGNB BSI. While this finding may be in part be explained by the exclusion of isolated fluoroquinolone resistance from our definition of ARGNB, some studies do suggest that fluoroquinolones have a mild impact on gut microbiome diversity which may limit colonization with ARGNB and thus infection with these pathogens 25,26 . Since the How Long study established that empiric antimicrobial therapy de‐escalation based on clinical criteria reduces antibiotic exposure among HM patients with febrile neutropenia, several other observational studies have supported the safety of this approach 21,27–32 .…”