Standard regimens for empirical therapy of native valve infective endocarditis

For empirical treatment of native valve endocarditis in adults and children, after taking 3 sets of blood for culture, as a 3-drug regimen, use:

benzylpenicillin 1.8 g (child: 50 mg/kg up to 1.8 g) intravenously, 4-hourly. For dosage adjustment in adults with kidney impairment, see benzylpenicillin dosage adjustment benzylpenicillin benzylpenicillin benzylpenicillin

PLUS

flucloxacillin 2 g (child: 50 mg/kg up to 2 g) intravenously, 4-hourly. For dosage adjustment in adults with kidney impairment, see flucloxacillin intravenous dosage adjustment flucloxacillin flucloxacillin flucloxacillin

PLUS

gentamicin intravenously; see Principles of aminoglycoside use for prescribing considerations and subsequent dosing¹ gentamicin gentamicin gentamicin

adult: see Gentamicin initial dose calculator for adults for initial dose

child younger than 18 years: 7 mg/kg up to 560 mg for initial dose² ³.

Flucloxacillin is more effective than vancomycin for methicillin-susceptible strains of Staphylococcus aureus (MSSA). If methicillin-resistant S. aureus (MRSA) endocarditis is suspected (eg people at increased risk of MRSA infection) or for patients with sepsis or septic shock, replace benzylpenicillin in the above regimen with vancomycin. Use:

vancomycin intravenously; for initial dosing, see Vancomycin dosing in adults or Intermittent vancomycin dosing for young infants and children. Loading doses are recommended for critically ill adults. vancomycin vancomycin vancomycin

If gentamicin is contraindicated, seek expert advice.

Modify therapy based on the results of culture and susceptibility testing. Once the pathogen has been identified, ideally establish the minimum inhibitory concentration (MIC) of the chosen antimicrobial.

Stop gentamicin when susceptibilities are known, except for streptococcal endocarditis or enterococcal endocarditis, when it may be necessary to continue gentamicin for several weeks using multiple-daily dosing for synergistic therapy – see also Gentamicin in the management of infective endocarditis.

¹ Gentamicin is the preferred aminoglycoside for empirical therapy of infective endocarditis because of its proven efficacy. Other aminoglycosides have less evidence in the treatment of infective endocarditis and clinical experience is lacking. If gentamicin is not available, amikacin or tobramycin may be initial alternatives for empirical therapy, to treat the possibility of gram-negative sepsis – for dosages, see Aminoglycoside dosing and administration.Return

² For children with obesity, use adjusted body weight to calculate the dose.Return

³ The maximum dose does not apply to children with septic shock or requiring intensive care support.Return