staphylococcal IE for penicillin MIC to vancomycin is >1 mg/L allergic (anaphylaxis) patients and in treatment of methicillinresistant staphylococci when vancomycin cannot be used Treatment of enterococcal Treatment of enterococcal spp.: spp.: ■ Use of ampicillin and ceftriaxone in the therapy of E ■ Ampicillin plus ceftriaxone faecalis IE, whether there is high-level resistance to (for aminoglycoside-resistant gentamicin or not, although the combination of ampicillin enterococci or aminoglycoside- and gentamicin is still advocated, with some experts intolerant patient) given as saying only 2 weeks of gentamicin needs to be given; this alternative therapy could be given as a single daily dose ■ Aminoglycoside give for whole duration of therapy Local policies should be adjusted for the specific testing methodologies used in their lab (CLSI or EUCAST) High doses of daptomycin are required (10 mg/kg) and, due to increase clearance of this drug in very young children and infants, specialist dosing advice needs to be sought AHA, American Heart Association; ESC, European Society of Cardiology; IE, infective endocarditis; MIC, minimum inhibitory concentration; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-sensitive Staphylococcus aureus Table 56.7 Antibiotic Treatment of Infective Endocarditis Due to Viridans Oral and Gastrointestinal Streptococci Antibiotic Dose Comments HIGHLY SUSCEPTIBLE STRAINS (MIC ≤0.1 MG/L) STANDARD 4-WEEK REGIMEN Penicillin G 200,000–300,000 U/kg/day Give 6 weeks if PVE divided 4 hourly doses Amoxicillin 200–300 mg/kg/day in 4–6 divided doses Ceftriaxone 100 mg/kg/day 1/day β-LACTAM ALLERGIC Vancomycin 40–45 mg/kg/day in 2–3 divided Serum trough levels should be doses 10–15 mg/L RELATIVELY RESISTANT STRAINS (MIC 0.2–2 MG/L) Penicillin G 200,000–300,000 U/kg/day Give 6 weeks if PVE divided in 4 hourly doses Serum trough levels 2 MG/L Vancomycin plus 40–45 mg/kg/day in 2–3 divided doses Give 6 weeks if PVE Serum trough levels should be 10–15 mg/L Gentamicin (for first 2 3–5 mg/kg/day 3 divided doses Serum trough levels