From the Guidelines
The recommended treatment for Streptococcus viridans endocarditis is a 4-week course of intravenous penicillin G (12-18 million units daily, divided into 4-6 doses) combined with gentamicin (3 mg/kg/day, divided into 2-3 doses) for the first 2 weeks, as outlined in the 2015 ESC guidelines for the management of infective endocarditis 1. For penicillin-allergic patients, ceftriaxone (2g IV daily) can be substituted, or vancomycin (15-20 mg/kg IV every 12 hours) if there's a severe beta-lactam allergy. Treatment duration may extend to 6 weeks for patients with symptoms lasting more than 3 months or those with prosthetic valve endocarditis. Key considerations in the management of Streptococcus viridans endocarditis include:
- Antibiotic susceptibility testing to guide treatment, especially in cases of reduced penicillin susceptibility 1
- Monitoring of blood cultures during treatment to confirm response
- Echocardiography to assess valve damage
- Surgical intervention for complications like severe valve regurgitation, heart failure, persistent bacteremia, or large vegetations
- Prophylactic antibiotics before dental procedures to prevent recurrence in patients with a history of viridans streptococcal endocarditis. The choice of antibiotic regimen should be based on the minimum inhibitory concentration (MIC) of the isolate, with penicillin G or ampicillin preferred for susceptible strains, and combination therapy with gentamicin for strains with reduced susceptibility 1.
From the FDA Drug Label
Vancomycin Hydrochloride for Injection, USP has been reported to be effective alone or in combination with an aminoglycoside for endocarditis caused by S. viridans or S. bovis. The recommended treatment for Streptococcus viridans (S. viridans) endocarditis is vancomycin alone or in combination with an aminoglycoside 2.
- Vancomycin is effective for the treatment of S. viridans endocarditis.
- It can be used alone or in combination with an aminoglycoside.
From the Research
Treatment Options for Strep Viridans Endocarditis
The treatment for strep viridans (Streptococcus viridans) endocarditis depends on the susceptibility of the bacteria to penicillin.
- For penicillin-susceptible strains, treatment typically involves a combination of penicillin and an aminoglycoside, such as gentamicin, for a duration of 4-6 weeks 3.
- For penicillin-resistant strains, treatment options are more limited and may involve the use of vancomycin, ceftriaxone, or other antibiotics, often in combination with an aminoglycoside 4, 5, 6.
Antibiotic Regimens
Various antibiotic regimens have been studied for the treatment of strep viridans endocarditis, including:
- Penicillin plus gentamicin 4, 6
- Ceftriaxone plus gentamicin 4, 6
- Vancomycin plus gentamicin 5, 6
- Ceftriaxone monotherapy 4
- Vancomycin monotherapy 5
Duration of Treatment
The duration of treatment for strep viridans endocarditis typically ranges from 4-6 weeks, depending on the severity of the infection and the patient's response to treatment 4, 3.
- Shorter treatment durations may be considered for select patients with uncomplicated endocarditis caused by penicillin-susceptible strains 3.
Surgical Intervention
Surgical intervention may be necessary in some cases of strep viridans endocarditis, particularly for patients with prosthetic valve infections or those who do not respond to antibiotic treatment 4, 6.