From the Guidelines
Suspected endocarditis should be treated with empiric antibiotics immediately, with a combination of vancomycin and gentamicin being a reasonable choice for initial empirical treatment in acute severely ill patients, as recommended by the 2015 ESC guidelines 1.
Treatment Approach
The treatment approach for suspected endocarditis involves several key steps:
- Initial empirical antibiotic therapy before the causative organism is identified
- Targeted antibiotic therapy once the specific bacteria are identified
- Possible surgical intervention for complicated cases
Empiric Antibiotic Therapy
For empiric therapy, the choice of antibiotics depends on the clinical presentation and the suspected causative organisms.
- For community-acquired native valve endocarditis, a combination of ampicillin, (flu)cloxacillin or oxacillin, and gentamicin may be used 1.
- For early prosthetic valve endocarditis (PVE) or nosocomial and non-nosocomial healthcare-associated endocarditis, vancomycin and gentamicin are recommended, with rifampin added for PVE 1.
Targeted Antibiotic Therapy
Once the causative organism is identified, targeted antibiotic therapy is administered.
- For Staphylococcus aureus, nafcillin or oxacillin is preferred for methicillin-sensitive strains, while vancomycin is used for resistant strains.
- For Streptococcus viridans, penicillin G or ceftriaxone is effective.
Surgical Intervention
Surgical intervention may be necessary for complicated cases, such as heart valve damage, persistent infection despite antibiotics, or large vegetations with embolic risk.
Monitoring and Follow-up
Regular blood tests, echocardiograms, and clinical assessments are crucial to monitor the response to treatment and adjust the therapy as needed, as recommended by the American Heart Association 1. The goal of treatment is to prevent morbidity, mortality, and improve quality of life by eradicating the infection and preventing complications, and the choice of antibiotics and treatment approach should be guided by the most recent and highest-quality evidence, such as the 2015 ESC guidelines 1 and the American Heart Association statement 1.
From the FDA Drug Label
Vancomycin Hydrochloride for Injection, USP is effective in the treatment of staphylococcal endocarditis Its effectiveness has been documented in other infections due to staphylococci, including septicemia, bone infections, lower respiratory tract infections, skin and skin structure infections. 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.
Treatment of possible endocarditis may involve the use of vancomycin alone or in combination with an aminoglycoside, depending on the causative organism.
- For staphylococcal endocarditis, vancomycin is effective.
- For endocarditis caused by S. viridans or S. bovis, vancomycin can be used alone or in combination with an aminoglycoside.
- For endocarditis caused by enterococci, vancomycin should be used in combination with an aminoglycoside 2.
Note that daptomycin is indicated for the treatment of right-sided infective endocarditis caused by methicillin-susceptible and methicillin-resistant S. aureus, but it is not indicated for left-sided infective endocarditis due to S. aureus 3.
From the Research
Treatment Strategies for Infective Endocarditis
- The treatment approach for paediatric endocarditis is similar to that for adult patients with endocarditis, with the therapeutic goal being to achieve sterilisation of the cardiac vegetations 4.
- The choice of antibacterial is dependent upon the susceptibility profile of the causative organism, with vancomycin or gentamicin recommended for enterococcal endocarditis 4.
- For staphylococcal endocarditis in patients with no prosthetic valve, oxacillin or nafcillin with or without gentamicin is the treatment of choice 4.
- In the case of endocarditis caused by methicillin-resistant S. aureus, vancomycin is commonly used in patients with no prosthetic valve and a combination of vancomycin, gentamicin and rifampicin (rifampin) for patients with prosthetic material 4.
Antibiotic Regimens
- A combination of aqueous penicillin G, nafcillin, and gentamicin is effective therapy for empiric antimicrobial therapy in urgent cases where the causative organism is not yet identified 5.
- For staphylococcal prosthetic-valve endocarditis, treatment with anti-staphylococcal penicillins, vancomycin, gentamicin, and rifampin is recommended, with the optimal duration of antibacterial treatment being 6 weeks 6.
- However, a systematic review and meta-analysis found that the existing clinical data do not suggest a benefit of either adjunctive gentamicin or rifampin in staphylococcal PVE, and that these agents may add nephrotoxicity, hepatoxicity, and risk of DDIs without benefit 7.
Oral Antibiotics
- Current clinical guidance from the American Heart Association and the European Society of Cardiology cite scenarios where oral antibiotics can be considered for treatment of IE, though these situations are relatively infrequent and data to show their non-inferiority is limited 8.
- A well-designed randomized clinical study reported favorable outcomes for partial oral antimicrobial therapy regimens given to patients with staphylococcal, streptococcal and enterococcal IE deemed clinically stable and without complications 8.
- Oral antibiotics, usually given in combination, were selected by infectious disease providers for their favorable pharmacologic properties and predicted bactericidal activity 8.