Table 6: Empirical antimicrobial therapy for infective endocarditis (IE)

without an identified pathogen.

Infection type

First-line treatment

Second-line treatment

Native valve

non-IV drug user

Penicillin G 20 million IU IV daily

or

Ampicillin 12 g IV daily plus

Dicloxacillin 2 g IV q6h

Gentamicin 1 mg/kg IV or IM q8h

Vancomycin 15 mg/kg q12h plus

Gentamicin 1 mg/kg or IM q8h

Native valve

IV drug user

Dicloxacillin 2 g IV q6h

Vancomycin 15 mg/kg q12h plus

Gentamicin 1 mg/kg or IM q8h

Prosthetic valve early IE

(< 2 months postoperative)

Vancomycin 15 mg/kg q12h plus

Gentamicin 1 mg/kg IV or IM q8h plus

Rifampin 600 mg daily

Prosthetic valve late IE

(> 2 months postoperative)

Ampicillin 12 g IV daily plus

Dicloxacillin 1 g IV q6h

Gentamicin 1 mg/kg q8h

Vancomycin 15 mg/kg q12h plus

Gentamicin 1 mg/kg or IM q8h