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| Values are valid only on day of printing. | |
Monitoring adequacy of blood concentration during
vancomycin therapy
This unit code is used whenever a specimen is submitted
or collected without collection timing 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-resistant Staphylococcus 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 ug/kg) and is usually administrated twice per day
by intravenous infusion. Dosing amount or interval must be
decreased to accommodate for reduced renal function.
VANCOMYCIN, PEAK
SERUM OR PLASMA
25.0-50.0 ug/mL
VANCOMYCIN, TROUGH
SERUM OR PLASMA
7.0-20.0 ug/mL
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. Typically 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.)
No significant cautionary statements
1. Mandell GL: Principles and Practice of Infectious Diseases. London,
Churchill Livingstone Press, 1995
2. Estes L, Wilson H: Mayo Guide to Antimicrobial Therapy. Mayo Clinic,
2005-2007