Unit Code 80141:
Vancomycin, Peak/Post
Useful For
Monitoring adequacy of blood concentration during vancomycin therapy
Clinical Information
Vancomycin is an antibiotic used to treat infections caused by gram-
positive organisms that are resistant to beta-lactam antibiotics, such
as methicillin-resistant staphylococci (MRSA), Staphylococcus viridans
group, penicillin/cephalosporin-resistant Streptococcus pneumoniae,
and penicillin/ampicillin-resistant Enterococcus species (in combination
with an aminoglycoside if cidal therapy is needed, eg, endocarditis).
The oral formulation, which is not absorbed, is used in the treatment of
pseudomembranous colitis caused by Clostridium difficile. Vancomycin
is also used for treatment of gram-positive organisms that are susceptible
to beta-lactams when patients are intolerant or have allergies to these
agents. It is an alternative to cefazolin for surgical prophylaxis.
Staphylococcal organisms are considered to have intermediate
resistance (vancomycin-intermediate Staphylococcus aureus [VISA])
with a minimal inhibitory concentration (MIC) of > or =4 ug/mL and are
resistant (vancomycin-resistantStaphylococcus aureus [VRSA]) with
a MIC of > or =16 ug/mL. Enterococcus organisms are considered
resistant to vancomycin (VRE) with a MIC of > or =16 ug/mL.
Vancomycin therapy is not effective for these resistant organisms.
Vancomycin is usually dosed based on the patient's weight (eg, 15-20
mg/kg) and is usually administered twice per day by intravenous infusion.
Dosing amount or interval must be decreased to accommodate for
reduced renal function.
Reference Values
VANCOMYCIN, PEAK
SERUM OR PLASMA
25-50 ug/mL
Interpretation
Trough levels correlate better with efficacy than peak levels, with target
trough levels of 7 ug/mL to 20 ug/mL, depending on the type of infection.
Goal trough level:
- 7 ug/mL to 15 ug/mL for most patients.
- 10 ug/mL to 15 ug/mL for more serious infections such as
bacteremia, endocarditis, and osteomyelitis.
- 15 ug/mL to 20 ug/mL may be appropriate for nosocomial
pneumonia or meningitis.
Peak levels are typically obtained when there are penetration limitations
(eg, central nervous system [CNS] infection) and when performing a
pharmacokinetic analyses in complex patients to more precisely adjust
doses. Typical peak levels are in the 25 ug/mL to 50 ug/mL range. The
higher end of this range is used when targeting higher trough levels.
Random levels may be ordered when attempting to determine when to
redose vancomycin in patients with renal impairment/dialysis.
Ototoxicity can be seen with high vancomycin peak levels (>80 ug/mL).
Vancomycin alone is not commonly associated with nephrotoxicity, but
nephrotoxicity is relatively common when given with other nephrotoxins
(eg, aminoglycosides, amphotericin, loop diuretics, etc.)
Cautions
No significant cautionary statements
Special Instructions and Forms
Clinical Reference
1. Mandell GL: Principles and Practice of Infectious Diseases. London,
Churchill Livingston Press, 1995
2. Estes L, Wilson J: Mayo Guide to Antimicrobial Therapy. Mayo Clinic,
2005-2007
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