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Unit Code 81749:
Vancomycin-Random

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Useful For

Monitoring adequacy of blood concentration during

vancomycin therapy

 

This unit code is used whenever a specimen is submitted

or collected without collection timing information

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-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.

Reference Values

VANCOMYCIN, PEAK

SERUM OR PLASMA

      25.0-50.0 ug/mL

 

VANCOMYCIN, TROUGH

SERUM OR PLASMA

      7.0-20.0 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. 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.)

Cautions

No significant cautionary statements

Clinical Reference

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

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