Vancomycin: an update.

Vancomycin is a narrow-spectrum glycopeptide antibiotic with potent antistaphylococcal activity. It is primarily active against gram-positive organisms. Bacterial resistance rarely develops due to its numerous modes of action. The toxic potential of vancomycin is less significant than previously thought. "Red neck syndrome" seems to be the most common side effect and appears to be caused by rapid intravenous infusion. It is characterized by erythema at the base of the neck and the upper back; hypotensive episodes may also occur. Nephrotoxicity and ototoxicity are rare. Relationships between toxicities and serum concentrations have not been established. The disposition of vancomycin after intravenous administration proceeds biphasically--rapid distribution followed by elimination. The drug is excreted primarily unchanged in the urine by glomerular filtration. Vancomycin clearance is reduced and elimination half-life is prolonged in patients with renal insufficiency. Various methods have been published to aid in dosing the drug in these patients. Vancomycin is the drug of choice in the treatment of methicillin-resistant staphylococcal infections. It is also useful in the treatment of gram-positive endocarditis and has been used as alternative therapy in the treatment of prophylaxis of gram-positive infections in penicillin-allergic patients. Oral vancomycin is the preferred therapy in antibiotic-associated colitis.