What is the treatment for Infective Endocarditis?

From the Guidelines

Endocarditis treatment should prioritize aggressive antibiotic therapy, with vancomycin being a key component for methicillin-resistant Staphylococcus aureus (MRSA) infections, at a dose of 30-60 mg/kg/day i.v. in 2-3 doses for 4-6 weeks, as recommended by the 2015 ESC guidelines 1. The choice of antibiotic therapy depends on the causative organism, with native valve endocarditis due to Staphylococcus spp. being treated with cloxacillin or oxacillin at 12 g/day i.v. in 4-6 doses for 4-6 weeks, or vancomycin for methicillin-resistant strains 1. Key considerations in endocarditis treatment include:

• Duration of therapy: typically 4-6 weeks for native valve endocarditis and ≥ 6 weeks for prosthetic valve endocarditis 1
• Dosing: vancomycin trough levels should be ≥ 20 mg/L, and gentamicin doses should be adjusted to minimize renal toxicity 1
• Combination therapy: rifampin and gentamicin may be added to vancomycin for prosthetic valve endocarditis, but their use should be carefully considered due to potential toxicity and resistance 1
• Monitoring: close surveillance for complications, including heart failure, embolic events, and antibiotic side effects, is crucial 1
• Surgical intervention: necessary in about 50% of cases, particularly with heart failure, uncontrolled infection, or prevention of embolic events 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. Vancomycin Hydrochloride for Injection, USP has been reported to be effective for the treatment of diphtheroid endocarditis Vancomycin Hydrochloride for Injection, USP has been used successfully in combination with either rifampin, an aminoglycoside, or both in early-onset prosthetic valve endocarditis caused by S. epidermidis or diphtheroids.

Vancomycin can be used for the treatment of endocarditis caused by:

• Staphylococcal infections
• S. viridans or S. bovis (alone or in combination with an aminoglycoside)
• Enterococci (in combination with an aminoglycoside)
• Diphtheroid infections
• Early-onset prosthetic valve endocarditis caused by S. epidermidis or diphtheroids (in combination with rifampin, an aminoglycoside, or both) 2

From the Research

Treatment Strategies for Endocarditis

• The treatment of endocarditis involves the use of antibiotics, with the choice of antibiotic depending on the identity and susceptibility of the infecting organism, as well as the type of cardiac valve involved 3, 4.
• For native valve endocarditis caused by methicillin-susceptible staphylococci, treatment with nafcillin, oxacillin, or cefazolin is recommended, with the addition of gentamicin for the first 3-5 days to accelerate clearing of bacteremia 4.
• For prosthetic valve endocarditis caused by staphylococcal organisms, treatment with three antibiotics (oral rifampin, gentamicin, and either nafcillin, oxacillin, cefazolin, or vancomycin) is recommended 4.
• The optimal duration of antibacterial treatment is 4 weeks for most native valve endocarditis and 6 weeks for prosthetic valve endocarditis 3.

Antibiotic Regimens

• A combination of penicillin and gentamicin is effective for enterococcal endocarditis, while vancomycin should be substituted for penicillin in cases of high-level resistance 4.
• For staphylococcal endocarditis, recent data reinforce the role of anti-staphylococcal penicillins, such as nafcillin or oxacillin, and vancomycin for methicillin-resistant isolates 3.
• The use of aminoglycosides, such as gentamicin, has been dramatically reduced over the last 20 years, and should be administered once daily for no longer than 2 weeks 3.

Treatment Outcomes

• The cure rate for endocarditis is high, with at least 85% of patients able to be cured with effective therapy 5.
• The choice of antibacterial is dependent on the susceptibility profile of the causative organism, and the therapeutic goal is to achieve sterilization of the cardiac vegetations 6.
• Limited and very low-quality evidence suggests that there are no conclusive differences between antibiotic regimens in terms of cure rates or other relevant clinical outcomes 7.