Vancomycin is a bactericidal glycopeptide antibiotic which is often co-prescribed with an aminoglycoside and which is not subject to crossed resistance with any other antibacterial. It acts by inhibiting cell wall synthesis in Gram-positive bacilli and its antibacterial spectrum of activity covers the staphylococci (including methicillin-resistant strains), the streptococci, the enterococci, the pneumococci and Gram-positive bacilli and anaerobes. Vancomycin may be given to treat infections such as septicemia, endocarditis, osteomyelitis (infection of the bone), colitis (that may occur after antibiotic treatment), some pneumonias, and meningitis. It is administered IV and is eliminated in the urine rapidly in its unmetabolized form. Hypersensitivity reactions (eg, rash, fever, reversible neutropenia and thrombocytopenia) may occur. Measuring the trough level is useful for detecting accumulation in the kidneys or the inner ear. The peak concentration measurement is used to check the bactericidal efficacy of the administered dose.