44 The Pharmacist’s Guide to Antimicrobial Therapy and Stewardship

II.5 INFECTIVE ENDOCARDITIS

Infective Endocarditis Comments Definition Endocarditis: inflammation of the lining of the heart valves and • Definition chambers. of IE based Infective endocarditis (IE): infection of the lining of the heart on modified valves and chambers. Duke criteria Modified Definitive IE Duke Pathological criteria Criteria • (+) cultured microorganisms or evidence of vegetation; or pathological lesions; or intracardiac abscess showing active endocarditis Clinical criteria • 2 major criteria; or • 1 major criterion and 3 minor criteria; or • 5 minor criteria Possible IE • 1 major criterion and 1 minor criterion; or • 3 minor criteria

Major Criteria Minor Criteria • Blood culture (+) for IE: at least 2 separate • Predisposing condition: blood cultures for a typical IE organism: viri- previous heart condition or dans streptococci, S. bovis, HACEK group, IV drug use S. aureus, or Enterococcus spp. • Fever >38°C (100.4°F) • Persistent bacteremia with any microorganism • Embolic evidence: arterial defined as: 2 (+) blood cultures drawn at least or pulmonary emboli, 12 hours apart; or 3 out of 3 (+) blood cultures mycotic aneurysm, drawn at least 1 hour apart or a majority of ≥4 intracranial hemorrhage, blood cultures drawn during any time period conjunctival hemorrhage, • Single (+) blood culture or serology for Janeway lesions ­ • Immunologic evidence: • Evidence of endocardial involvement glomerulonephritis, Osler • Echocardiogram (+) for IE nodes, Roth spots, (+) {{TEE strongly recommended for patients rheumatoid factor with prosthetic valves and TTE recom- • (+) blood cultures that do mended as first test in other patients not meet a major criterion or serologic evidence of active IE

Common Most common bacterial cause of infective endocarditis: strepto- Offend- cocci, staphylococci, and enterococci ing Gram +: Patho- • Coagulase negative (S. epidermidis. S. lugdunensis) gens • Coagulase positive (S. aureus) • Enterococci (E. faecalis and E. faecium) • Other streptococci (S. bovis) • Viridans streptococcus II.5 Infective Endocarditis 45

Infective Endocarditis Comments Common Gram −: Offend- • species ing • (Salmonella species, E. coli, Serratia Patho- ­marcescens, P. mirabilis, Klebsiella species) gens • Enterobacteriaceae (Salmonella species, E. coli, Serratia ­marcescens, P. mirabilis, Klebsiella species) • HACEK (H. parainfluenzae, H. aphrophilus, H. influenza, H. paraphrophilus, actinomycetemcomitans, hominis, , , K. denitrificans) • Fungi: Fungal IE is rare. • Aspergillus spp. If diagnosed, • Candida spp. surgical replacement of infected valve is warranted.

INFECTIVE ENDOCARDITIS—CULTURE PENDING

Valve Empiric Treatment Comments Native • −sulbactam 3 g IV Q6h Adjust vancomycin dose to achieve plus target trough of 10−20 mcg/mL • Gentamicin 1 mg/kg IV Q8h Target gentamicin peak: 3−4 mcg/mL or Target gentamicin trough: <1 mcg/mL • Vancomycin 15 mg/kg IV Q12h Can often just monitor gentamicin Prosthetic • Vancomycin 15 mg/kg IV Q12h trough to ensure drug clearance plus Consider the most likely pathogen based • Gentamicin 1 mg/kg IV Q8h on risk factors or initial gram stain plus • Rifampin 600 mg PO Q24h • Linezolid 600 mg IV Q12h May be used in patients intolerant to or vancomycin • Daptomycin ≥8 mg/kg IV Q24h

INFECTIVE ENDOCARDITIS—CULTURE POSITIVE

Duration Organism Valve Definitive Treatment (weeks) Comments Enterococcus Native • Ampicillin 2 g IV Q4h 4−6 Target gentamicin peak: spp. or 3−4 mcg/mL (PCN • PCN G 3 million/units IV Q4h Target gentamicin susceptible) plus trough: <1 mcg/mL • Gentamicin 1 mg/kg IV Q8h Streptomycin may be an alternative for genta- micin resistant strains