Infective Endocarditis (Native valve)

Clinical definition:

Infection of the endothelial surface of the heart. Symptoms may be variable and non-specific. Ideally, the diagnosis should be confirmed and an organism identified on blood culture before commencing treatment. However, if the patient presents with severe disease, empiric treatment should be started and directed at staphylococci and streptococci.

 

Neonate, Infant, Child & Adolescent

Preferred antibiotic choice
DrugFormulationDosageDuration
Combination therapy with:

Benzylpenicillin (IV)

PLUS

Cloxacillin (IV)

PLUS

Gentamicin (IV)

Benzylpenicillin- Powder for injection: 600 mg (= 1 million IU); 3 g (= 5 million IU) (sodium or potassium salt) in vialo   First week of life (7 days or less): 100 000 IU/kg/dose 8 hourly

o   8 days of age & older: 125 000 IU/kg/dose 6 hourly, maximum dose 5 million IU 6 hourly

4 – 6 weeks

 

Cloxacillin- Powder for injection: 500 mg (as sodium salt) in vialo   First week of life (7 days or less): 50 mg/kg/dose 12 hourly

o   8 – 28 days: 50 mg/kg/dose 8 hourly

o   28 days & older: 50 mg/kg/dose 6 hourly, maximum dose 3 g 6 hourly

Gentamicin- Injection: 10 mg, 40 mg (as sulfate) / mL in 2 mL vial3 mg/kg/dose once daily, maximum dose 360 mgFirst 2 weeks of therapy
Alternative antibiotic choice(s)
If Benzylpenicillin is not available, substitute with:

Ampicillin (IV)

Treat in combination with

Cloxacillin (IV)

PLUS

Gentamicin (IV), as above.

Ampicillin- Powder for injection: 500 mg, 1 g (as sodium salt) in vialo   First week of life (7 days or less): 50 mg/kg/dose 8 hourly

o   8 days of age & older: 50 mg/kg/dose 6 hourly, maximum dose 2 g 6 hourly

4 – 6 weeks
If Cloxacillin is not available, substitute with:

Cefazolin (IV)

Treat in combination with Benzylpenicillin (IV) (Or Ampicillin (IV)

PLUS

Gentamicin (IV), as above.

Cefazolin- Powder for injection: 1 g (as sodium salt) in vialo   First week of life (7 days or less): 50 mg/kg/dose 12 hourly

o   8 days of age & older: 50 mg/kg/dose 8 hourly, maximum dose 4 g 8 hourly

 

4 – 6 weeks
In case of confirmed drug allergy or medical contraindication
DrugFormulationDosageDuration
Vancomycin (IV)

PLUS

Gentamicin (IV)

 

Vancomycin- Injection: 500 mg, 1 g vial (as hydrochloride)15 mg/kg/dose 6 hourly4 – 6 weeks
Gentamicin- Injection: 10 mg, 40 mg (as sulfate) / mL in 2 mL vial1.5 mg/kg/dose 12 hourlyFirst 2 weeks of therapy

 

Principles of Stewardship:

  • For suspected infective endocarditis cases, 3 blood cultures should be obtained in rapid succession from 3 anatomic sites within 6 hours before initiation of antibiotic therapy.
  • If a pathogen is identified in blood culture, antibiotic treatment should be tailored to that pathogen, in line with appropriate guidelines. The pathogen and anatomical site may affect the duration of therapy.
  • Therapeutic drug monitoring and renal function monitoring on patients treated with vancomycin and/or gentamicin.

Notes:

  • Obtain expert advice from a cardiologist and/or infectious diseases specialist (if available) in all cases of endocarditis (native valve or prosthetic valve endocarditis)