What are the appropriate antibiotic choices for Streptococcus (Streptococcal) bacteremia likely originating from pneumonia?

From the Guidelines

For streptococcus bacteremia likely originating from pneumonia, the first-line treatment is intravenous penicillin G (3-4 million units every 4 hours) or ceftriaxone (1-2g IV daily), as recommended by the Infectious Diseases Society of America/American Thoracic Society consensus guidelines 1. The choice of antibiotic is based on the excellent activity of these agents against most streptococcal species and their good penetration into lung tissue.

• Penicillin G and ceftriaxone are the preferred agents due to their narrow spectrum of activity and low risk of promoting antibiotic resistance.
• For penicillin-allergic patients, vancomycin (15-20 mg/kg IV every 8-12 hours) or linezolid (600 mg IV/oral twice daily) are appropriate alternatives, as they have broad-spectrum activity against streptococcal species, including those resistant to penicillin.
• Treatment duration should typically be 10-14 days for uncomplicated bacteremia, extending to 4-6 weeks if endocarditis or other metastatic infections are suspected, as suggested by the Surviving Sepsis Campaign guidelines 1.
• Blood cultures should be repeated after 48-72 hours of antibiotics to confirm clearance of bacteremia, and narrowing therapy based on susceptibility testing is essential once available.
• For severe infections or if there's concern for resistant strains, combination therapy with gentamicin (1 mg/kg IV every 8 hours) may be considered for the first few days, as recommended by the Surviving Sepsis Campaign guidelines 1.
• Supportive care, including oxygen therapy, fluid management, and monitoring for complications such as empyema or endocarditis, is also crucial for optimal outcomes.
• The most recent guidelines from the Surviving Sepsis Campaign 1 emphasize the importance of daily assessment for de-escalation of antimicrobial therapy and suggest that measurement of procalcitonin levels can be used to support shortening the duration of antimicrobial therapy in sepsis patients.

From the FDA Drug Label

1 INDICATIONS & USAGE

1.1 Nosocomial Pneumonia Linezolid is indicated for the treatment of nosocomial pneumonia caused by Staphylococcus aureus (methicillin-susceptible and -resistant isolates) or Streptococcus pneumoniae [see Clinical Studies (14)].

1. 2 Community-acquired Pneumonia Linezolid is indicated for the treatment of community-acquired pneumonia caused by Streptococcus pneumoniae, including cases with concurrent bacteremia, or Staphylococcus aureus (methicillin-susceptible isolates only) [see Clinical Studies (14)].

Appropriate antibiotic choices for Streptococcal bacteremia likely originating from pneumonia include linezolid, as it is indicated for the treatment of community-acquired pneumonia caused by Streptococcus pneumoniae, including cases with concurrent bacteremia 2.

From the Research

Antibiotic Choices for Streptococcal Bacteremia

• The choice of antibiotic for Streptococcus pneumoniae bacteremia, likely originating from pneumonia, depends on various factors including the severity of the infection, patient's age, and antibiotic resistance patterns 3, 4, 5, 6, 7.
• Beta-lactam antibiotics such as penicillin G, amoxicillin, amoxicillin/clavulanate, cefuroxime, cefotaxime, and ceftriaxone are commonly recommended for non-meningeal pneumococcal infections, including pneumonia and sepsis 6.
• For meningitis, cefotaxime or ceftriaxone, with the addition of vancomycin until susceptibility is known, is recommended 6.
• Fluoroquinolones, streptogramins, and oxazolidinones have shown good microbiologic and clinical efficacy against penicillin-resistant pneumococci 5.
• The use of polysaccharide or conjugated vaccines is highly recommended to prevent pneumococcal infections 5.

Resistance Patterns

• The incidence of penicillin resistance in strains of S. pneumoniae is increasing, with rates approaching 40% in some areas of the United States 6.
• Erythromycin and ceftriaxone resistance rates have increased over the years, but were significantly reduced in adult groups 7.
• Levofloxacin resistance and multidrug-resistant (MDR) rates were higher in adult groups 7.
• The MDR rate significantly increased during the recent 10 years, as well as in patients with a history of hospitalization within 90 days and sinusitis 7.

Treatment Duration

• Shorter antibiotic courses (5-10 days) may be appropriate in patients with S. pneumoniae bacteremia secondary to community-acquired pneumonia 3.
• The effectiveness of short versus long antibiotic durations for S. pneumoniae bacteremia was evaluated in a retrospective study, which found no significant difference in clinical failure rates between the two groups 3.