Introduction Vancomycin is a bactericidal antibiotic obtained from strains of Streptomyces orientalis and discovered in 1956 at the Eli Lilly Research Laboratories.3 It is active against staphylococci, hemolytic streptococci, enterococci, pneumococci, corynebacteria, and clostridia. All clinically isolated staphylococci are sensitive to vancomycin's action, and it has been used against a wide variety of staphylococci infections with excellent results.6,7 Vancomycin is particularly useful in the treatment of infections due to staphylococci which are resistant to other antibiotics such as penicillin, tetracycline, and erythromycin, and it is considered by some authorities to be among the drugs of choice in treating severe staphylococcic infections which are resistant to the commonly used antibiotics.1,2 High blood levels are readily attained following intravenous administration, and staphylococci are generally sensitive to less than 5μg. of vancomycin per milliliter. Vancomycin is currently available only as an intravenous preparation—Vancocin, intravenous—a product of Eli Lilly Laboratories. When