Vancomycin

Step 1:  Prescribe a stat LOADING dose using the vancomycin calculator or use the table below based on Actual Body Weight:     

N.B. The loading dose is based solely on weight and does not take account of renal function.  Maintenance doses are based on renal function and estimated clearance of vancomycin.  Occasionally the estimate of a patient’s clearance of vancomycin maybe so high that the calculator maintenance dose will be higher than the loading dose.  In these circumstances give the higher maintenance dose as the loading dose.

Step 2: Calculate and prescribe a maintenance dose and frequency using the Vancomycin calculator or calculate creatinine clearance (CrCl) via MDCalc  (age, height, weight and serum creatinine required) and use the table below.  Give the first maintenance dose 12, 24 or 48 hours after the loading dose.

*try to avoid inconvenient dosing schedules.  Suggested infusion times are 6am and 6pm, 10am and 10pm

Note that patients who have unusual clinical characteristics e.g. weight <40kg or >120kg, age >90 years may require dose adjustments and closer monitoring.  Seek pharmacy advice.

Some patients may require individualised dosing regimens out with the table above.  For example, the total daily dose can be split into 3 doses given 8 hourly.  This approach is especially useful for patients who are requiring higher doses than in the table above to produce the recommended trough concentrations.  E.g. 1500mg 12 hourly (=3000mg /day) could be prescribed as 1000mg 8 hourly and 750mg 12 hourly (1500mg/day) as 500mg 8 hourly.  Seek pharmacy advice.

Step 3:  Monitor vancomycin levels:   

Concentrations are meaningless unless the dose and sample times and recorded accurately.

Take a trough sample (pre-dose) prior to the 3rd maintenance dose for 12 hourly regimes, prior to the 2nd maintenance for those on 24 hourly regimes and prior to the 1st maintenance dose for those on 48 hourly regimes.

Thereafter monitor levels every  2 – 3 days if renal function is stable or daily if the patient has unstable renal function. 

Do not withhold dose whilst awaiting levels, unless renal function is deteriorating.

Monitor renal function and check for signs of ototoxicity daily.

Target vancomycin concentrations:

 Non-deep seated infection (e.g. uncomplicated SSTI):  10 – 15 mg/L

Deep seated or severe infection (e.g. bacteraemia, endocarditis, osteomyelitis, meningitis, HAP):  15 - 20mg/L

Step 4:  Adjustment of the vancomycin dosage regimen:

 **Always check that doses have been administered on time and the sampling time is appropriate before interpreting the result**

Seek advice from pharmacy if you need help to interpret the result.

If the measured concentration is unexpectedly HIGH or LOW, consider the following:

-  Were the dose and sample times recorded accurately?

-  Was the correct dose administered and on time?

-  Was the sample taken from the line used to administer the drug?

-  Was the sample taken during drug administration?

-  Has renal function declined or improved?

-  Does the patient have oedema or ascites?

(This guidance has been developed NHS Greater Glasgow and Clyde and applies to situations where a patient has stable renal function and a dose of vancomycin has been delayed unintentionally (for example due to loss of intravenous access))

Vancomycin dose - unintended delay of ≤50% of dosing interval:

Vancomycin dose - unintended delay of >50% of dosing interval: