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Vancomycin is a time-dependent bactericidal antibiotic that inhibits cell wall synthesis.
Pharmacology
Vancomycin is not appreciably absorbed from a normal GI tract after oral administration. Given parenterally, it penetrates into bile and pleural, pericardial, synovial, and ascitic fluids. However, penetration into even inflamed CSF is low and erratic. Vancomycin is excreted unchanged by glomerular filtration.
Indications
Vancomycin is active against
However, many strains of enterococci and some strains of S. aureus are resistant.
Vancomycin is the drug of choice for serious infection and endocarditis caused by the following:
However, vancomycin is less effective than antistaphylococcal β-lactams for S. aureus endocarditis. Vancomycin is used with other antibiotics when treating methicillin-resistant coagulase-negative staphylococcal prosthetic valve endocarditis or enterococcal endocarditis. Vancomycin has also been used as an alternative drug for pneumococcal meningitis caused by strains with reduced penicillin sensitivity; however, the erratic penetration of vancomycin into CSF (especially during concomitant use of dexamethasone) and reports of clinical failures make it less than optimal when used alone to treat pneumococcal meningitis. Before dental procedures likely to result in bacteremia are done, vancomycin is used to prevent endocarditis in penicillin-allergic high-risk patients who cannot tolerate oral antibiotics.
Oral vancomycin is used to treat Clostridium difficile–induced diarrhea (pseudomembranous colitis) only if patients do not respond to metronidazole.
Contraindications
Vancomycin is contraindicated in patients who have had an allergic reaction to it.
Use During Pregnancy and Breastfeeding
Vancomycin has not had adverse effects in animals, and evidence in human studies is inadequate. Oral vancomycin tablets are in pregnancy category B (animal studies show no risk and human evidence is incomplete, or animal studies show risk but human studies do not). Oral-solution vancomycin and IV vancomycin are in category C (animal studies show some risk, evidence in human and animal studies is inadequate, but clinical benefit sometimes exceeds risk).
Vancomycin enters breast milk, and so its use during breastfeeding is discouraged; however, because oral absorption is poor from a normal GI tract, adverse effects in infants are usually considered unlikely.
Adverse Effects
The main concern is
Hypersensitivity reactions (eg, rash, fever, reversible neutropenia and thrombocytopenia) may occur, especially when therapy lasts for > 2 wk. Nephrotoxicity is rare unless high doses are used or an aminoglycoside is given concomitantly. Phlebitis occurs uncommonly during IV infusion. Infusion should be given over at least 60 min to avoid the red-person syndrome, a histamine-mediated reaction that can cause pruritus and flushing on the face, neck, and shoulders.
Dose-related ototoxicity is unusual with current formulations.
Dosing Considerations
Doses used for meningitis must be higher than usual. Dose reduction is required in renal insufficiency. In critically ill patients, serum levels should be measured after the 2nd or 3rd dose and kept between 10 and 15 μg/mL (trough levels).
Vancomycin MIC has been increasing in the past decade. S. aureus with vancomycin MIC of ≤ 2 μg/mL are considered sensitive; those with vancomycin MIC of 4 to 8 μg/mL are considered intermediate, and those with vancomycin MIC of > 8 μg/mL are considered resistant. However, infections due to S. aureus with vancomycin MIC of 2 to 8 μg/mL may respond suboptimally to standard dosing and require higher doses with trough levels between 15 to 20 μg/mL, but this approach may be complicated by increased rates of nephrotoxicity.
Last full review/revision July 2009 by Matthew E. Levison, MD
Content last modified July 2009
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