Contra-indications

• Hypersensitivity

Cautions

• To avoid the risk of 'red-neck/red-man syndrome', pain or muscle spasm, ensure that the administration rate is not faster than 500mg per hour.
• Concurrent administration of neurotoxic and/or nephrotoxic agents increases the risk of vancomycin toxicity.  Review therapy and consider amending or withholding nephrotoxic drugs during treatment with vancomycin. Where possible, avoid co-administration with the following:
        o amphotericin
        o potent diuretics
        o aminoglycosides
        o NSAIDs
        o ACE inhibitors
• The above list is not exhaustive – consult the Summary of Product Characteristics eSPC for a full list (www.medicines.org.uk).
• Due to potential ototoxicity, vancomycin should be avoided in patients with previous hearing loss.

STEP 1:  Prescribe the loading dose and maintenance dosage regimen using the vancomycin prescription form. On the drug chart, prescribe “Vancomycin as per chart”.

• To reduce the risk of mortality, commence vancomycin administration within 1 hour of recognising sepsis.
• If creatinine is known – use the vancomycin calculator available via the NHS Highland and Western Isles antimicrobial app.  If the calculator is not available, use the flow chart to determine the loading dose and maintenance dose.
• The guidelines below in Table 1 (loading dose) and Table 2 (maintenance dose) can be used if the online calculator is not available.  The dose amount and dosage interval are based on estimated creatinine clearance and actual body weight.
• If creatinine is not known – calculate and prescribe a loading dose based on actual body weight (Table 1).  Calculate the maintenance dose once the creatinine is available.

Estimation of creatinine clearance (CrCl)

The following 'Cockcroft Gault' equation can be used to estimate creatinine clearance (CrCl)

 Cautions

• Use actual body weight or maximum body weight whichever is lower. See SAPG Maximum Body Weight Table (internet access required).
• In patients with low creatinine (below 60micromol/L) use 60micromol/L.
• Note: Use of estimated glomerular filtration rate (eGFR) is not recommended.

LOADING DOSE - Table 1: Initial vancomycin LOADING dose

*Glucose 5% may be used in patients with sodium restriction.

NB The loading dose is based on weight only so does not take account of renal function. When using the online calculator, on rare occasions a patient's clearance of vancomycin may be so high that the maintenance dose is higher than the loading dose. In these circumstances, give the maintenance dose as the loading dose.

MAINTENANCE DOSAGE REGIMEN

Give the first maintenance infusion 12, 24 or 48 hours after the loading infusion according to dose interval provided by the vancomycin calculator available via the NHS Highland and Western Isles antimicrobial app or Table 2.

Table 2: Vancomycin MAINTENANCE dosage regimen

*Glucose 5% may be used in patients with sodium restriction. Doses up to 2500mg can be diluted in 500mL fluid.

The daily dose can be split into 3 equal doses and given 8-hourly. this approach is especially useful for patients who require high doses as it produces higher trough concentrations. For example, 1500mg 12-hourly (3000mg per day) could be prescribed as 1000mg 8-hourly and 750mg 12-hourly (1500mg per day) could be prescribed as 500mg 8-hourly.

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

• Due to wide variability in the handling of vancomycin, early analysis of a vancomycin concentration is required to ensure that the dosage regimen is appropriate. 
• Take a trough sample (pre-dose) within 48 hours of starting therapy then every 2 to 3 days, or daily if the patient has unstable renal function.
• Monitor creatinine daily.
• Record the exact time of all vancomycin samples on the vancomycin prescribing chart AND on the sample request form.
• If renal function is stable, give the next dose before the trough result is available.  If renal function is deteriorating, withhold until the result is available then follow the advice in Table 3.
  

Target vancomycin concentrations

• Target trough concentration range: 10  to 20mg/L.
• If the patient is seriously ill (severe or deep-seated infections), the target range is 15 to 20mg/L. If the measured concentration is below 15mg/L, consider increasing the dose amount or reducing the dosage interval (see 8-hourly dosing above). 
• If the patient is failing to respond, seek advice from microbiology or an infection specialist.
  

Adjustment of the vancomycin dosage regimen

• Always check that the dosage history and sampling time are appropriate before interpreting the result.
• Seek advice from pharmacy or microbiology 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?
• 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?

Table 3:  Adjustment of Vancomycin Dosage Regimen

If in doubt, take another sample before modifying the dosage regimen and/or contact pharmacy for advice.

General points

• record the exact times of all measured concentrations on the vancomycin prescription chart.
• Undertake pre-prescribing checks to assess the risk of toxicity.
  • Monitor creatinine daily. Seek advice if renal function is unstable (eg a change in creatinine of more than 15 to 20%).
  • Signs of renal toxicity include increase in creatinine or decrease in urine output/oliguria.
  • Consider an alternative agent if creatinine is rising or the patient becomes oliguric.
  • Vancomycin may increase the risk of aminoglycoside induced ototoxicity - use caution if co-prescribing.
• Reassess the dose and continue or prescribe a dosage change.
• Document the action taken in the medical notes.
• Review the need for vancomycin daily.

Flow diagram for initiating vancomycin pulsed infusion in adult patients