Monitoring and dosing of vancomycinmo
| Monitoring and dosing of vancomycin |
Introduction
Prospective studies on the value of monitoring vancomycin levels for either predicting efficacy or reducing toxicity are lacking. Further, there is no consensus on what target levels should be used for monitoring. Nevertheless, monitoring is considered important in some patient groups, especially those with abnormal volumes of distribution (eg severe burns or generalised oedema) or significant renal impairment (including those receiving renal replacement therapy). Monitoring is also recommended for all patients undergoing treatment for serious methicillin-resistant Staphylococcus aureus (MRSA) infections to reduce the risk of underdosing and thereby possible selection of vancomycin-intermediate and hetero-resistant vancomycin-intermediate strains.
The current monitoring convention is to measure trough concentrations. In patients with normal renal function, the most widely accepted target trough concentrations are 10 to 20 mg/L in patients receiving 12-hourly dosing, and 15 to 25 mg/L in patients receiving 6-hourly dosing (see Table 2.29).
In patients with renal impairment, less frequent dosing is required to achieve the target trough concentration (see Table 2.30).
Vancomycin starting doses and target trough concentrations for patients with normal renal function (Table 2.29)
| Age | Starting dose [NB1] (use actual body weight) | Target trough concentration (mg/L) |
| neonates <34 weeks postconceptional age | 25 mg/kg 24-hourly | 10–20 |
| neonates 34–44 weeks postconceptional age | 25 mg/kg 12-hourly | 10–20 |
| infants and children <12 years | 30 mg/kg up to 1 g 12-hourly | 10–20 |
| or 15 mg/kg up to 500 mg 6-hourly [NB2] | 15–25 | |
| adults and children >12 years | 25 mg/kg up to 1 g 12-hourly [NB3] | 10–20 |
| or 12.5 mg/kg up to 500 mg 6-hourly [NB2] | 15–25 | |
| NB1: Dose may need adjustment following evaluation of vancomycin blood level after first dose. NB2: In these guidelines, 6-hourly dosing is recommended only for treatment of meningitis. NB3: Many patients, particularly the obese, will require higher doses to achieve the target trough concentration. | ||
Vancomycin starting doses and target trough concentrations for adult patients with impaired renal function [NB1] (Table 2.30)
| Creatinine clearance [NB2] | Starting dose [NB3] (use actual body weight) | Target trough concentration (mg/L) | |
| (mL/s) | (mL/min) | ||
| >0.8 | >50 | 25 mg/kg up to 1 g 12-hourly | 10–20 |
| 0.17–0.8 | 10–50 | 25 mg/kg up to 1 g 24-hourly | 10–20 |
| <0.17 | <10 | 25 mg/kg up to 1 g, check levels at 48 hours | 10–20 |
| NB1: Seek specialist advice for vancomycin dosing in children with impaired renal function. NB2: Creatinine clearance can be approximated using the modified Cockcroft-Gault formula. NB3: Dose interval may need adjustment following evaluation of vancomycin blood level after first dose. Repeat levels once to twice a week or more frequently if there is rapidly changing renal function. | |||
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