From the Guidelines
Endocarditis treatment should always prioritize aggressive antibiotic therapy, with initial empiric treatment involving a combination of vancomycin and gentamicin, as recommended by the 2015 ESC guidelines 1.
Key Considerations
- The choice of antibiotic therapy should be tailored to the specific causative organism once identified, with consideration of the valve type (native or prosthetic) and the timing of symptom onset.
- For native valve endocarditis, coverage for Staphylococcus aureus, β-hemolytic streptococci, and aerobic Gram-negative bacilli is reasonable in cases of acute presentation, while subacute presentations may require coverage for S aureus, Viridans group streptococci (VGS), HACEK, and enterococci 1.
- Prosthetic valve endocarditis (PVE) requires coverage for staphylococci, enterococci, and aerobic Gram-negative bacilli if symptom onset is within 1 year of valve placement, and for staphylococci, VGS, and enterococci if symptom onset is more than 1 year after valve placement 1.
Treatment Recommendations
- For methicillin-susceptible staphylococcal endocarditis, (flu)cloxacillin or oxacillin is recommended, with the addition of gentamicin not advised due to lack of clinical benefit and increased renal toxicity 1.
- For methicillin-resistant staphylococcal endocarditis, vancomycin is the preferred treatment, with consideration of alternative therapies such as daptomycin in certain cases 1.
- Surgical intervention is necessary in cases with heart failure, uncontrolled infection, large vegetations (>10mm), or recurrent embolic events.
Monitoring and Follow-Up
- Regular blood cultures should be performed to confirm clearance of infection.
- Echocardiograms should be used to monitor vegetation size and valve function.
- Careful monitoring for complications like heart failure or embolic events is essential.
- Antibiotic therapy must be administered for the full recommended course to prevent relapse, given the limited blood supply to infected cardiac valves, which makes it difficult for antibiotics to completely eradicate the infection 1.
From the FDA Drug Label
Vancomycin Hydrochloride for Injection, USP is effective in the treatment of staphylococcal endocarditis 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. For endocarditis caused by enterococci (e.g., E. faecalis), vancomycin has been reported to be effective only in combination with an aminoglycoside. Septicemia and Endocarditis caused by susceptible Gram-positive organisms including Streptococcus spp., penicillin G-susceptible staphylococci, and enterococci. The addition of an aminoglycoside may enhance the effectiveness of ampicillin when treating streptococcal endocarditis Gentamicin injection has also been found effective when used in conjunction with a penicillin-type drug for treatment of endocarditis caused by group D streptococci
Treatment for endocarditis may include:
- Vancomycin alone or in combination with an aminoglycoside for endocarditis caused by S. viridans or S. bovis
- Vancomycin in combination with an aminoglycoside for endocarditis caused by enterococci
- Ampicillin for endocarditis caused by susceptible Gram-positive organisms
- Gentamicin in combination with a penicillin-type drug for treatment of endocarditis caused by group D streptococci 2, 3, 4
From the Research
Treatment Options for Endocarditis
- The treatment of endocarditis depends on the type of bacteria causing the infection, the location of the infection, and the patient's overall health 5, 6, 7, 8.
- For native valve endocarditis, the optimal duration of antibacterial treatment is 4 weeks, while for prosthetic-valve endocarditis, it is 6 weeks 5.
- The use of aminoglycosides, such as gentamicin, has been reduced over the last 20 years, and it is now recommended to be administered once daily for no longer than 2 weeks 5.
- For staphylococcal endocarditis, anti-staphylococcal penicillins, such as nafcillin or oxacillin, are recommended for methicillin-susceptible isolates, while vancomycin is recommended for methicillin-resistant isolates 5, 6, 7, 8.
- For enterococcal endocarditis, a combination of penicillin or ampicillin with gentamicin is recommended, while vancomycin should be substituted for penicillin when high-level resistance is present 6, 7, 8.
Antibiotic Regimens
- Various antibiotic regimens have been compared in clinical trials, including quinolone plus standard treatment, fosfomycin plus imipenem, and partial oral treatment versus conventional intravenous treatment 9.
- However, the evidence is limited and of low to very low quality, making it difficult to determine the most effective antibiotic regimen for the treatment of endocarditis 9.
- The American Heart Association recommends specific antibiotic regimens for the treatment of endocarditis, including aqueous penicillin or ceftriaxone for streptococcal endocarditis, and vancomycin or gentamicin for enterococcal endocarditis 6, 7.
Prophylactic Antibiotic Therapy
- Prophylactic antibiotic therapy is recommended for procedures that are associated with the occurrence of bacteremia, such as dental extractions and genitourinary or gastrointestinal surgical procedures 7.
- The American Heart Association recommends specific prophylactic antibiotic regimens, including ampicillin plus gentamicin or vancomycin plus gentamicin for high-risk patients 7.