Canterbury DHB

Context

Vancomycin Dosing Guidelines (Adults)

Most patients will receive vancomycin by intermittent infusions. Infectious Diseases may start patients on continuous infusions, especially if ongoing treatment is required in the community after discharge.

These guidelines do not apply to patients on renal replacement therapy – seek advice from your Ward Pharmacist.

In This Section

Intermittent Infusions

Continuous Infusions

Intermittent Infusions

  1. Loading dose:

    Calculate the patient's body mass index (BMI)

    All patients starting vancomycin should receive a loading dose based on actual body weight and infection severity (irrespective of renal function):

    In severe infections, dose at the upper end of the range. The risks of under treating during the first 24 to 48 hours of treatment outweigh the risks of over treating.

    Prescribe in MedChart as a stat dose by infusion (see 3. Administration advice below).

    Vancomycin has a long infusion time – give other IV antimicrobial agents with shorter infusion times first if unable to give them concurrently.

    Take blood for vancomycin concentrations (peak and trough) off the first (loading) dose – early vancomycin concentration monitoring enables dose individualisation. See 4. Monitoring.

  2. Maintenance dose:

    Calculate the patient's creatinine clearance (CrCl) using the Cockcroft and Gault calculator.

    Alternatively, the estimated glomerular filtration rate (eGFR) supplied by the laboratories can be used for patients who are not at the extremes of body size.

    Use CrCl and Table 1 to guide the initial maintenance dose. Initiate maintenance dosing 12 hours after the start of the loading dose.

    Prescribe in MedChart as regular doses by infusion (see 3. Administration advice).

    Table 1: Initial vancomycin maintenance dose (intermittent infusions)

    CrCl (mL/min)

    Dose administered 12-hourly

    approximate mg/kg actual body weight dose

    rounded mg dose to be prescribed*

    > 90

    15 to 22.5 mg/kg 12-hourly

    1000 to 2000 mg 12-hourly

    60 to 90

    10 to 15 mg/kg 12-hourly

    750 to 1500 mg 12-hourly

    45 to 59

    7.5 to 10 mg/kg 12-hourly

    500 to 1000 mg 12-hourly

    30 to 44

    5 to 7.5 mg/kg 12-hourly

    375 to 500 mg 12-hourly

    < 30

    Consult Infectious Diseases to discuss alternative antimicrobial agents.

    *Round to the nearest 250 mg (half of a 500 mg vial) where able.

  3. Administration:

    Give diluted solution via a central venous catheter (CVC), if possible: Vancomycin is an irritant and must be given diluted in a compatible fluid, e.g. sodium chloride 0.9%. Maximum concentration is usually 5 mg/mL via a peripheral line, or 10 mg/mL (sometimes up to 20 mg/mL) via a CVC. Administer via a CVC if possible, although this should not delay initiation of treatment.

    Administer slowly to minimise development of a vancomycin infusion reaction characterised by hypotension, pruritus, and erythema (typically upper body and may be difficult to detect in darker skins) secondary to histamine release. The usual maximum rate is now 1000 mg/hour. Slow the rate of infusion (e.g. to 500 mg/hour) if signs of an infusion reaction occur.

  4. Monitoring:

    Venepuncture is the ideal sampling method for vancomycin concentrations – avoid sampling from the line used to administer vancomycin:

    Create a Patient Alert on MedChart to ensure blood is taken for required vancomycin concentrations.

    Continue with the initial maintenance dose recommended in these guidelines until the Ward Pharmacist has provided further dosing advice (will occur during usual working hours so there may be a delay). If subsequent dosing advice includes bringing the next dose forward, cease the existing vancomycin prescription and create a new prescription (instead of editing the existing prescription).

    The measured vancomycin concentrations will be used to estimate the area under the concentration-time curve (AUC) across 24 hours. The target AUC24 is usually 400 to 600 mg/L.h, which is the equivalent of average concentrations of 17 to 25 mg/L over 24 hours. A higher AUC24 target may be appropriate for some infections (e.g. central nervous system infections, endocarditis) and organisms (minimum inhibitory concentration ≥ 1.5 mg/L): seek advice from Infectious Diseases/Clinical Microbiology.

    Monitor creatinine regularly to detect possible vancomycin-induced nephrotoxicity or the need to monitor vancomycin concentrations more closely with changing vancomycin elimination.

    Check for ototoxicity. Stop vancomycin if this is suspected to be due to this agent.

Continuous Infusions

Continuous infusions of vancomycin should not be initiated without Infectious Diseases recommendation.

Prescribe on the paper chart for infusions and flag this in MedChart by prescribing "Chart exists" (i.e. a "dummy drug").

Patients transitioning from intermittent to continuous vancomycin infusion will not require a loading dose. Consult Ward Pharmacist for dosing advice.

The following applies to patients commencing vancomycin by continuous infusion without prior intermittent dosing:

  1. Loading dose:

    All patients should receive a loading dose (see 1. Loading dose under Intermittent Infusions), unless transferring from intermittent infusions.

  2. Maintenance dose:

    Calculate the patient's creatinine clearance (CrCl) using the Cockcroft and Gault calculator. Alternatively, the estimated glomerular filtration rate (eGFR) supplied by the laboratories can be used for patients who are not at the extremes of body size.

    Use Table 2 below to determine the initial maintenance dose. The first maintenance dose should start immediately after completion of the loading dose.

    Give the vancomycin continuous infusion by a central venous catheter where possible to minimise extravasation and phlebitis.

    Table 2: Vancomycin maintenance dose (continuous infusion only)

    CrCl (mL/min)

    Dose per 24 hours in 250 mL or 500 mL of compatible IV fluid via a central line or peripheral line

    Central line: usually up to 10 mg/mL (sometimes up to 20 mg/mL e.g. in fluid restriction). Give required dose over 24 hours in a 250 mL or 500 mL bag of compatible fluid.

    Peripheral line: usual maximum concentration is 5 mg/mL. Give required dose (up to 2500 mg) in a 500 mL bag of compatible fluid over 24 hours.

    > 90

    2500 mg

    60 to 90

    2000 mg

    45 to 59

    1500 mg

    30 to 44

    1000 mg

    < 30

    Contact Infectious Disease to discuss alternative antimicrobial therapy.

  3. Monitoring:

    Take one blood sample for vancomycin concentrations 24 hours after starting the maintenance infusion. The target steady-state concentration is usually 17 to 25 mg/L. For dosing advice, contact the Ward Pharmacist or the pharmacist on call after hours (before 10.30 pm unless the next bag must be started before 8 am).

    Monitor vancomycin concentrations, renal function, and ototoxicity as directed above for intermittent infusions.

Information about this Canterbury DHB document (90761):

Document Owner:

Not assigned (see Who's Who)

Last Updated:

May 2019 (Antimicrobial Dosing Guidelines (Adults) - Gentamicin/Tobramycin and Vancomycin)

Next Review Due:

May 2022

Keywords:

Note: Only the electronic version is controlled. Once printed, this is no longer a controlled document.

Topic Code: 90761