Is Levaquin (levofloxacin) effective against Streptococcus anginosus?

Levofloxacin Coverage of Streptococcus anginosus

Levofloxacin (Levaquin) does have activity against Streptococcus anginosus and has been successfully used in clinical practice, particularly for intracranial infections caused by this organism, though it is not typically a first-line agent for most streptococcal infections. 1

Clinical Evidence for S. anginosus Coverage

• A 2022 retrospective study of 107 pediatric patients with S. anginosus intracranial infections demonstrated that levofloxacin-based oral regimens were highly effective and well tolerated, with only 1 treatment failure noted (in a patient who didn't fill their prescription). 1

• In this cohort, 61 patients were successfully transitioned to exclusive oral therapy after a median of 37 days of intravenous antibiotics, overwhelmingly using levofloxacin-based regimens. 1

• The study specifically highlighted that levofloxacin was effective for treating serious S. anginosus infections, including epidural and parenchymal brain infections. 1

Microbiological Activity

• Levofloxacin demonstrates broad-spectrum activity against Gram-positive organisms, including streptococcal species. 2, 3

• The drug has documented activity against viridans group streptococci (which includes S. anginosus as part of the Streptococcus anginosus group). 4

• Levofloxacin achieves high tissue concentrations that exceed plasma levels in many sites, including lung, skin, and other tissues, which is advantageous for deep-seated infections. 2

Important Caveats and Limitations

• While levofloxacin has activity against S. anginosus, fluoroquinolones are generally NOT recommended as first-line therapy for most streptococcal infections. 5, 4

• The IDSA strongly recommends against fluoroquinolones for streptococcal pharyngitis due to their unnecessarily broad spectrum and the need to preserve fluoroquinolone effectiveness. 5, 4

• For serious S. anginosus infections like necrotizing fasciitis, the combination of clindamycin plus penicillin remains the recommended treatment, not fluoroquinolones. 4

When Levofloxacin May Be Appropriate for S. anginosus

• Deep-seated or intracranial S. anginosus infections where oral step-down therapy is needed after initial intravenous treatment. 1

• Situations where penicillin-based regimens have failed or cannot be used due to allergy or intolerance. 4

• When excellent tissue penetration is required for complicated infections (abscesses, osteomyelitis). 2

• Patients requiring transition from intravenous to oral therapy to avoid central line complications. 1

Resistance Considerations

• Fluoroquinolone resistance in streptococci is increasing, though overall resistance of S. pneumoniae to levofloxacin remains <1% in the United States. 6

• Institutions using fluoroquinolone therapy must closely monitor local resistance patterns over time. 4