Glycopeptides have been recommended as therapy for endocarditis. MICs and M
BCs of vancomycin and teicoplanin were compared for 100 isolates from patie
nts with proven bacterial endocarditis. MICs were generally lower for teico
planin and tolerance to both agents was common. Almost all isolates of ente
rococci were tolerant to both glycopeptides. Among the streptococci, 78% we
re tolerant to teicoplanin and 57% to vancomycin. Similar findings were dem
onstrated for staphylococci. Although isolates appear sensitive to glycopep
tides, bactericidal activity cannot always be predicted. If a glycopeptide
is indicated for treatment of endocarditis, combination therapy with a suit
able aminoglycoside should be considered unless MBC testing can be performe
d.