Streptococci with Penicillin MICs of < 0.1 µ g/ml
Regimen A Penicillin, G, 12-18 million units per day IV in divided doses q4th x 4 weeks
Regimen B Penicillin as in regimen A plus gentamicin, 1mg/kg IV q8h. both x 2 weeks
Regimen C Ceftriaxone, 2 g IV or IM once daily x 4 weeks
Regimen D Vancomycin 15 mg/kg IV q12h x 4weeks
Streptococci with Penicillin G MICs of > 0.1 But < 0.5 µg/ml
Regimen E Penicillin G, 18 million units per day IV in divided dose q4th x 4 weeks, plus Gentamycin 1 mg/kg IV q8th for the first 2 weeks; or regimen D if patient is allergic to Penicillin.
Enterococci or Streptocci with Penicillin G MICs of > 0.5 µg/ml OR Nutritionally variant viridans Streptococci
Regimen F Penicillin G, 18-30 million units per day IV, or ampicillin, 12 g/d IV, in divided dose q4th, plus gentamycin, 1 mg/kg IV q8h both x 4-6 weks
Regimen G Vancomycin, 15 mg/kg IV q12h, plus gentamycin as in regimen F, both x 4-6 weeks.
Methicillin-susceptible Staphylococci on a native valve
Regimen H Nafcillin or oxacillin, 2g IV q4h x4-6 weeks, with or without gentamycin, 1mg/kg IV q8h x the first 3-5 d
Regimen I Cefazolin* 2g IV q8h x 4-6 weeks, with or without gentamycin as in regimenH
Regimen J Vancomycin, 15 mg/kg IV q12h x 4-6 weeks, with or without gentamycin as in regimen H
Methicillin-resistant Staphylococci or Corynebacterium Spp. On a native valve
Regimen K Vancomycin a sin regimen J with or without gentamycin as in regimen H. for staphylococci; continue gentamycin x 4-6 weeks for Corynebacterium Spp.
Above organisms on a prosthetic valve
Streptococcus or enterococci : Regimen F or G Streptococci :Penicillin or vancomycin x 6 weeks with gentamycin x the first 2 weeks or longer. Enterococci: Penicillin or vancomycin plus an aminoglycoside x 6-8weeks.
Methicillin - Susceptible staphylococci: Regimen H, I, or J x 6-8 weeks, with gentamicin x the first 2 week and rifampin (300 mg orally q8h) for the entire course methicillin – resistant staphylococci : Regimen J x 6-8 weeks, with gentamycin x the first 2weeks and rifampin (300 mg orally q8h) for the entire course.
*HACEK bacteria
Regimen L Use regimen C
Another first-generation cephalosporin maybe used instead of cefazolin.
Note: Serum concentrations of gentamycin should be about 3 mmg/ml 1 hr after a 20 to 30 min. IV infusion or IM injection. Streptomycin may be substituted for gentamycin inRegimens B, E, F and G at 7.5 mg/kg IM every 12 h;serum concentration should be about mg/mL 1 h after injection. The maximal dose of vancomycin is 1 g every 12h;serum concentrations of vancomycin 1h after completion of the infusion shoule be 30-45 mg/mL.