Guidelines
Interpreting Vancomycin Levels

Interpreting Vancomycin Levels

LOW TARGET (10-15 mg/L)

Trough levels should be collected 60 min (or less) before next scheduled dose is due. Ensure level was collected at correct time before adjusting dose based on the reported result.

For high trough levels, recommended method of dose adjustment is to keep the maintenance dose unchanged while lengthening the dosing interval. GENERALLY, If renal function remains stable then doubling the length the interval (i.e. from q12h to q24h) will decrease the trough level by ~ 50%. The reverse is true for dosage increases.

If on q18h interval, change interval to q12h

Otherwise, decrease level by 12 hour increment (i.e. if q36h interval change to q24h)

No change (in desired range)

CONTACT PHARMACY FOR ANY RESULT > 20 mg/L

If q18h and level between 15-20 mg/L, increase interval to q24h

Otherwise, if level 15-20 mg/L increase level by 12h increment (i.e. if q12h change to q24h)

HIGH TARGET (15-20 mg/L)

See above regarding the timing of levels and dose adjustment

Contact Pharmacy for any level < 10 mg/L regardless of dosing interval

If on q18h and level between 10-15 mg/L, shorten dosage interval to q12h

Otherwise, if level between 10-15 mg/L, shorten interval by 12 hrs (i.e. if q36h change to q24h)

No Change (in desired range)

Contact Pharmacy for any level > 20 mg/L regardless of dosing interval

Depending on clinical situation and extent to which level is elevated, consider lengthening level by 12 hrs (i.e. from q12h to q24h)

For levels > 25 mg/L or rapidly declining renal function, more drastic dose reduction/lengthening of interval may be required. Pharmacist consult recommended. repeat level should be less than 20 mg/L before therapy is resumed.

For q18h dosing and levels 20-25 mg/L, lengthen interval to q24h