Levofloxacin Activity Against Burkholderia pseudomallei
Levofloxacin does have in vitro activity against Burkholderia pseudomallei, but it should not be used as standard therapy for melioidosis because fluoroquinolones like moxifloxacin have demonstrated poor clinical efficacy and resistance patterns, and levofloxacin is not included in any guideline-recommended treatment regimens. 1, 2
Evidence for Levofloxacin Activity
- Levofloxacin was identified in a screening study as having inhibitory effects against B. pseudomallei K96243, with a minimal inhibitory concentration (MIC) below 12 μg/ml for 5 tested strains 3
- However, the closely related fluoroquinolone moxifloxacin showed only 37.5% susceptibility among Malaysian B. pseudomallei isolates, and both moxifloxacin and azithromycin are explicitly not recommended for melioidosis treatment due to resistance 4, 2
Why Levofloxacin Is Not Recommended
- B. pseudomallei is inherently resistant to many antibiotics, and fluoroquinolones are not part of standard treatment protocols 1, 5
- In vitro susceptibility testing from 1978-2003 showed that the majority of B. pseudomallei strains were resistant to moxifloxacin, indicating that fluoroquinolones as a class have limited clinical utility 4
- Ertapenem, azithromycin, and moxifloxacin should not be used due to inherent resistance patterns 1
Novel Case Report Exception
- A single 2025 case report described successful salvage therapy with levonadifloxacin (not standard levofloxacin) for B. pseudomallei osteomyelitis after the patient developed severe allergic reactions to trimethoprim-sulfamethoxazole, ceftazidime, and meropenem-associated leukopenia 6
- This represents the first reported use of a benzoquinolizine fluoroquinolone derivative in melioidosis, but this is a different compound than standard levofloxacin and was used only as salvage therapy when all standard options failed 6
Standard Treatment Recommendations
- The recommended treatment for severe melioidosis is intravenous meropenem or imipenem for at least 14 days, followed by trimethoprim-sulfamethoxazole for 3-6 months 1, 7
- Ceftazidime is an acceptable alternative if carbapenems are unavailable 1, 7
- All clinical B. pseudomallei isolates show 100% susceptibility to meropenem and imipenem, making these the most reliable treatment options 4, 7, 2
Clinical Bottom Line
While levofloxacin may demonstrate some in vitro activity, it is not a guideline-recommended agent for melioidosis treatment and should only be considered in exceptional salvage situations when all standard therapies have failed or are contraindicated 1, 6, 3.