From the Guidelines
Empiric treatment for endocarditis should involve a combination of antibiotics that provide broad coverage, with the specific regimen depending on the type of valve affected and the clinical presentation, as recommended by the 2015 ESC guidelines 1. The choice of empirical treatment depends on several considerations, including whether the patient has received previous antibiotic therapy, the type of valve affected (native or prosthetic), and the place of infection (community, nosocomial, or non-nosocomial healthcare-associated) 1. For native valve endocarditis, the recommended regimen is vancomycin 30-60 mg/kg/day IV in 2-3 doses, plus gentamicin 3 mg/kg/day IV or IM in 1 dose, as outlined in the 2015 ESC guidelines 1. For prosthetic valve endocarditis, treatment should include vancomycin 30 mg/kg/day IV in 2 doses, plus gentamicin 3 mg/kg/day IV or IM in 1 dose, with the addition of rifampin 900-1200 mg IV or orally in 2 or 3 divided doses for early PVE (<12 months post surgery) 1. It is essential to obtain blood cultures before starting antibiotics whenever possible and to consult with an infectious diseases specialist to define the most appropriate choice of therapy, especially in cases of culture-negative endocarditis 1. The treatment duration typically ranges from 4-6 weeks, depending on the causative organism and presence of complications, and therapy should be narrowed accordingly to reduce the risk of antibiotic resistance and adverse effects once the specific pathogen is identified 1. Key considerations in the management of endocarditis include:
- Obtaining multiple sets of blood cultures before starting antibiotics
- Consulting with an infectious diseases specialist to define the most appropriate choice of therapy
- Providing broad-spectrum coverage with antibiotics until culture results are available
- Narrowing therapy to the specific pathogen once identified to reduce the risk of antibiotic resistance and adverse effects
- Monitoring for potential complications and adjusting treatment accordingly.
From the FDA Drug Label
- 9 Persisting or Relapsing S. aureus Bacteremia/Endocarditis Patients with persisting or relapsing S. aureus bacteremia/endocarditis or poor clinical response should have repeat blood cultures. If a blood culture is positive for S aureus, minimum inhibitory concentration (MIC) susceptibility testing of the isolate should be performed using a standardized procedure, and diagnostic evaluation of the patient should be performed to rule out sequestered foci of infection. Appropriate surgical intervention (e.g., debridement, removal of prosthetic devices, valve replacement surgery) and/or consideration of a change in antibacterial regimen may be required.
The empiric treatment for endocarditis is not explicitly stated in the provided drug label. However, it mentions that daptomycin may be used to treat S. aureus bacteremia/endocarditis. The label also emphasizes the importance of minimum inhibitory concentration (MIC) susceptibility testing and diagnostic evaluation to guide treatment decisions. Additionally, it notes that surgical intervention may be necessary in some cases. 2
From the Research
Empiric Treatment for Endocarditis
The empiric treatment for endocarditis involves the use of antibiotics to target the most common causative organisms, including staphylococci, streptococci, enterococci, and Gram-negative bacilli.
- The choice of antibiotic regimen depends on the suspected causative organism and the patient's clinical presentation 3.
- For staphylococcal endocarditis, anti-staphylococcal penicillins, such as oxacillin or nafcillin, are recommended for methicillin-susceptible isolates, while vancomycin is recommended for methicillin-resistant isolates 3, 4.
- The use of aminoglycosides, such as gentamicin, is generally limited to the first 2 weeks of treatment, and their use has decreased over the last 20 years 3.
- For enterococcal endocarditis, vancomycin or gentamicin is recommended, according to guidelines from the American Heart Association 4.
- The optimal duration of antibacterial treatment is typically 4 weeks for native valve endocarditis and 6 weeks for prosthetic valve endocarditis 3.
Comparison of Antibiotic Regimens
Several studies have compared the effectiveness of different antibiotic regimens for the treatment of endocarditis, including:
- A comparison of quinolone (levofloxacin) plus standard treatment versus standard treatment alone, which found uncertain effects on all-cause mortality 5, 6.
- A comparison of daptomycin versus low-dose gentamicin plus an anti-staphylococcal penicillin or vancomycin, which found uncertain effects on cure rates 5, 6.
- A comparison of cloxacillin plus gentamicin versus a glycopeptide (vancomycin or teicoplanin) plus gentamicin, which found uncertain effects on cure rates 5, 6.
- A comparison of ceftriaxone plus gentamicin versus ceftriaxone alone, which found no conclusive differences in terms of cure rates 5, 6.
Continuous versus Intermittent Infusion of Oxacillin
A retrospective study compared the outcomes of continuous-infusion (CI) oxacillin versus intermittent-infusion (II) oxacillin for the treatment of infective endocarditis caused by methicillin-susceptible Staphylococcus aureus (MSSA) 7.