From the Guidelines
Oral levofloxacin is a suitable treatment option for Viridans streptococcus bacteremia.
Key Considerations
- The recommended dose of levofloxacin is 500mg once daily 1.
- The duration of treatment typically ranges from 10 to 14 days, depending on the severity of the infection and the patient's clinical response.
- Levofloxacin has demonstrated effective bactericidal activity against Viridans streptococcus, particularly in situations with increased risk for oral mucositis-related invasive viridans group streptococcal infection 1.
Important Factors
- Minimum Inhibitory Concentration (MIC): In cases where the MIC is ≤2mg/L, levofloxacin has shown effective bactericidal activity against Viridans streptococcus 1.
- Resistance Epidemiology: Understanding local resistance epidemiology is critical to the decision of whether to implement fluoroquinolone prophylaxis, including levofloxacin 1.
- Adverse Effects: Patients and families should be informed about potential short- and long-term fluoroquinolone-related adverse effects prior to administration of levofloxacin 1.
Clinical Guidance
- Levofloxacin is preferred over ciprofloxacin due to its broad-spectrum activity against important organisms, including viridans group streptococci 1.
- If levofloxacin is not available or cannot be used, ciprofloxacin is an alternative, although it has reduced activity against gram-positive bacteria, including viridans group streptococci 1.
From the Research
Effectiveness of Oral Levofloxacin
- The effectiveness of oral levofloxacin in treating Viridans streptococcus bacteremia is supported by several studies 2, 3.
- A study published in 1999 found that levofloxacin was effective in treating experimental endocarditis caused by viridans group streptococci, with a minimum inhibitory concentration (MIC) of 1 mg/L 2.
- Another study published in 1996 found that levofloxacin had excellent antimicrobial activity against 350 clinical isolates of streptococci, including penicillin-resistant strains 3.
Limitations and Concerns
- However, a study published in 2016 found that breakthrough viridans streptococcal bacteremia occurred in 15.2% of allogeneic hematopoietic stem cell transplant recipients receiving oral levofloxacin prophylaxis, with all isolates being resistant to levofloxacin 4.
- This suggests that levofloxacin may not be effective in preventing viridans streptococcal bacteremia in all cases, particularly in patients with certain underlying conditions.
Dosage and Treatment
- The optimal dosage and treatment regimen for oral levofloxacin in treating Viridans streptococcus bacteremia is not clearly established, but studies suggest that higher doses (e.g. 500mg twice daily or 1g once daily) may be more effective than standard doses (e.g. 500mg once daily) 2, 5, 6.
- The choice of treatment regimen should be based on individual patient factors, including the severity of the infection and the presence of any underlying conditions.