From the FDA Drug Label
15 to 20 million units/day for 2 weeks(*) 250,000 units/kg/day in equal doses every 4 hours for 10 to 14 days 10 million units/day in 4 equally divided doses with the duration of therapy depending on the type of infection
The recommended treatment for Group B strep (Streptococcus agalactiae) bacteremia is penicillin (IV) at a dose of 15 to 20 million units/day for 2 weeks, or 250,000 units/kg/day in equal doses every 4 hours for 10 to 14 days, or 10 million units/day in 4 equally divided doses with the duration of therapy depending on the type of infection 1.
- Key considerations:
- The dosage regimens may vary depending on the severity of the infection and the patient's renal function.
- The treatment should be continued for at least 48 to 72 hours after the patient becomes asymptomatic.
- Penicillin G is relatively nontoxic, and dosage adjustments are generally required only in cases of severe renal impairment.
From the Research
The recommended treatment for Group B strep (Streptococcus agalactiae) bacteremia is intravenous penicillin G at a dose of 3-4 million units every 4 hours for at least 10-14 days. For patients with penicillin allergy, alternatives include ceftriaxone 2g IV daily or vancomycin 15-20 mg/kg IV every 8-12 hours (not to exceed 2g per dose) 2. Susceptibility testing should be performed to guide therapy, especially in serious infections. For complicated bacteremia or if endocarditis is suspected, longer treatment courses of 4-6 weeks may be necessary. Addition of gentamicin (1 mg/kg IV every 8 hours) for synergy may be considered in severe cases like endocarditis, though this practice is becoming less common due to nephrotoxicity concerns. Source control is essential, so any potential focus of infection (such as abscess) should be identified and addressed. Group B strep remains universally susceptible to penicillin, which is why it remains the first-line therapy. The bactericidal activity of beta-lactams against the cell wall of this gram-positive organism makes them particularly effective in clearing the bloodstream infection.
Some key points to consider in the treatment of Group B strep bacteremia include:
- The importance of identifying and addressing any potential focus of infection, such as an abscess
- The need for susceptibility testing to guide therapy, especially in serious infections
- The potential for longer treatment courses in cases of complicated bacteremia or suspected endocarditis
- The consideration of alternative antibiotics, such as ceftriaxone or vancomycin, in patients with penicillin allergy
- The potential risks and benefits of adding gentamicin for synergy in severe cases.
It's worth noting that the most recent study 2 suggests that oral antibiotic step-down therapy may be appropriate for the treatment of uncomplicated Streptococcal bacteremia, with consideration of factors such as patient comorbidities, type of infection, source control, and clinical progress. However, this approach should be used with caution and in consultation with an infectious disease specialist.