Antibiotic Treatment for Infective Endocarditis Caused by Common Organismsa | ||
| ORGANISM(S) | DRUG (DOSE, DURATION) | COMMENTS |
|---|---|---|
| Streptococci | ||
| Penicillin-susceptible streptococci, S. gallolyticus (MIC ≤0.12 µg/mLb ) | • Penicillin G (2-3 mU IV q4h for 4 weeks) | Can use ampicillin or amoxicillin (2 g IV q4h) if penicillin is unavailable. |
| • Ceftriaxone (2 g/d IV as a single dose for 4 weeks) | Can use ceftriaxone in pts with non-immediate penicillin allergy. | |
| • Vancomycinc (15 mg/kg IV q12h for 4 weeks) | Use vancomycin in pts with severe or immediate β-lactam allergy. | |
• Penicillin G (2-3 mU IV q4h) or ceftriaxone (2 g IV qd) for 2 weeks plus Gentamicind (3 mg/kg qd IV or IM, as a single dosee or divided into equal doses q8h for 2 weeks) | Avoid 2-week regimen when risk of aminoglycoside toxicity is increased and in prosthetic-valve or complicated endocarditis. | |
| Relatively penicillin-resistant streptococci, S. gallolyticus (MIC >0.12 µg/mL and <0.5 µg/mLf ) | • Penicillin G (4 mU IV q4h) or ceftriaxone (2 g IV qd) for 4 weeks plus Gentamicind (3 mg/kg qd IV or IM, as a single dosee or divided into equal doses q8h for 2 weeks) | Can use ampicillin or amoxicillin (2 g IV q4h) if penicillin is unavailable. Penicillin alone at this dose for 6 weeks or with gentamicin during the initial 2 weeks is preferred for prosthetic-valve endocarditis caused by streptococci with penicillin MICs of ≤0.1 µg/mL. |
| • Vancomycinc as noted earlier for 4 weeks | Use vancomycin if unable to tolerate penicillins. Ceftriaxone alone or with gentamicin can be used in pts with non-immediate β-lactam allergy. | |
| Moderately penicillin-resistant streptococci (MIC, ≥0.5 µg/mL and <8 µg/mLg ); Granulicatella, Abiotrophia, or Gemella spp. | • Penicillin G (4-5 mU IV q4h) or ceftriaxone (2 g IV qd) for 6 weeks plus Gentamicind (3 mg/kg qd IV or IM as a single dosee or divided into equal doses q8h for 6 weeks) | Preferred for PVE caused by streptococci with penicillin MICs of >0.1 µg/mL. |
| • Vancomycinc as noted earlier for 4 weeks | Regimen is preferred by some. | |
| Enterococcih | ||
| Penicillin G (4-5 mU IV q4h) plus gentamicind (1 mg/kg IV q8h), both for 4-6 weeks | Can treat NVE for 4 weeks if symptoms last <3 months. Treat PVE and NVE with >3 months of symptoms for 6 weeks. Can abbreviate gentamicin course in some pts (see text). Can use streptomycin (7.5 mg/kg q12h) in lieu of gentamicin if there is not high-level resistance to streptomycin. | |
| • Ampicillin (2 g IV q4h) plus gentamicind (1 mg/kg IV q8h), both for 4-6 weeks | Can use amoxicillin in lieu of ampicillin (same dose). | |
| • Vancomycinc (15 mg/kg IV q12h) plus gentamicind (1 mg/kg IV q8h), both for 6 weeks | Use vancomycin plus gentamicin only for penicillin-allergic pts (preferable to desensitize to penicillin) and for isolates resistant to penicillin/ampicillin. | |
| • Ampicillin (2 g IV q4h) plus ceftriaxone (2 g IV q12h), both for 6 weeks | Use for E. faecalis isolates with or without high-level resistance to gentamicin and streptomycin or for pts at high risk for aminoglycoside nephrotoxicity (creatinine clearance rate <50 mL/min; see text). | |
| Staphylococci (S. aureus and coagulase-negative) | ||
| MSSA infecting native valves (no foreign devices) | • Nafcillin, oxacillin, or flucloxacillin (2 g IV q4h for 4-6 weeks) | Can use penicillin (4 mU q4h) if isolate is penicillin susceptible (i.e., does not produce β-lactamase); 6-week course preferred |
| • Cefazolin (2 g IV q8h for 4-6 weeks) | Can use cefazolin regimen for pts with non-immediate penicillin allergy; 6-week course preferred | |
| • Vancomycinc (15 mg/kg IV q12h for 4-6 weeks) | Only use vancomycin for pts with immediate (urticarial) or severe penicillin allergy; see text regarding addition of gentamicin, fusidic acid, or rifampin. A 6-week course is preferred. | |
| MRSA infecting native valves (no foreign devices) | • Vancomycinc (15 mg/kg IV q8-12h for 4-6 weeks) | No role for routine use of rifampin (see text). Consider high-dose daptomycin treatment (see text) for MRSA with vancomycin MIC >1.0 or persistent bacteremia during vancomycin therapy. |
| MSSA infecting prosthetic valves | • Nafcillin, oxacillin, or flucloxacillin (2 g IV q4h for 6-8 weeks) plus Gentamicind (1 mg/kg IM or IV q8h for 2 weeks) plus • Rifampini (300 mg PO q8h for 6-8 weeks) | Use gentamicin during initial 2 weeks; determine susceptibility to gentamicin before initiating rifampin (see text); if pt is highly allergic to penicillin, use regimen for MRSA; if β-lactam allergy is of the minor non-immediate type, cefazolin can be substituted for oxacillin, nafcillin, or flucloxacillin. |
| MRSA infecting prosthetic valves | • Vancomycinc (15 mg/kg IV q12h for 6-8 weeks) plus Gentamicind (1 mg/kg IM or IV q8h for 2 weeks) plus Rifampini (300 mg PO q8h for 6-8 weeks) | Use gentamicin during initial 2 weeks; determine gentamicin susceptibility before initiating rifampin. |
| HACEK Organisms | ||
| • Ceftriaxone (2 g/d IV as a single dose for 4 weeks) | Can use another third-generation cephalosporin at comparable dose. | |
| • Ampicillin/sulbactam (3 g IV q6h for 4 weeks) | If the isolate is susceptible, ciprofloxacin (400 mg IV q12h) can be used. | |
| Coxiella burnetii | ||
| • Doxycycline (100 mg PO q12h) plus hydroxychloroquine (200 mg PO q8h), both for at least 18 (native valve) or 24 (prosthetic valve) months | Follow serology to monitor response during treatment (antiphase I IgG and IgA decreased 4-fold and IgM antiphase II negative) and thereafter for relapse. | |
| Bartonella spp. | ||
• Doxycycline (100 mg q12h PO) for 6 weeks plus Gentamicin (1 mg/kg IV q8h for 2 weeks) | If doxycycline is not tolerated, use azithromycin (500 mg PO qd). Some experts recommend that doxycycline be continued for 3-6 months unless all infection is resected surgically. | |
a Regimens adapted from the guidelines of the American Heart Association, the European Society of Cardiology (ESC), and to a lesser extent the British Society for Antimicrobial Chemotherapy (BSAC). Doses of gentamicin, streptomycin, and vancomycin must be adjusted for reduced renal function. Ideal body weight is used to calculate doses of gentamicin and streptomycin per kilogram (men = 50 kg + 2.3 kg per inch over 5 feet; women = 45.5 kg + 2.3 kg per inch over 5 feet).
b MIC ≤0.125 µg/mL per ESC and BSAC.
c Vancomycin dose is based on actual body weight. Adjust for trough level of 10-15 µg/mL for streptococcal and enterococcal infections and 15-20 µg/mL for staphylococcal infections.
dAminoglycosides should not be administered as single daily doses for enterococcal endocarditis and should be introduced as part of the initial treatment. Target peak and trough serum concentrations of divided-dose gentamicin 1 h after a 20- to 30-min infusion or IM injection are ∼3.5 µg/mL and ≤1 µg/mL, respectively; target peak and trough serum concentrations of streptomycin (timing as with gentamicin) are 20-35 µg/mL and <10 µg/mL, respectively.
eNetilmicin (4 mg/kg qd, as a single dose) can be used in lieu of gentamicin.
f MIC >0.125 µg/mL and ≤2.0 µg/mL per ESC; MIC >0.125 µg/mL and ≤0.5 µg/mL per BSAC.
g MIC >2.0 µg/mL per ESC; treat with regimen for enterococci (BSAC).
h Antimicrobial susceptibility must be evaluated; see text.
i Rifampin increases warfarin and dicumarol requirements for anticoagulation.
Abbreviations: MIC, minimal inhibitory concentration; MRSA, methicillin-resistant S. aureus; MSSA, methicillin-sensitive S. aureus; NVE, native-valve endocarditis; PVE, prosthetic-valve endocarditis.