Objective Vancomycin is a renally excreted glycopeptide antibiotic used for treating gram-positive bacterial infections. Blood level monitoring is required to maximise efficacy and minimise toxicity. In 2006, target serum trough levels for vancomycin were increased from 5–10 mg/l to 10–15 mg/l,1 2 3 but dose recommendations for children in the BNF-C remained unchanged at 15 mg/kg every 8 h (three time a day). The BNF-C provides no additional information on dose adjustment in renal impairment, or how to adjust doses if target levels are not achieved.3
Following an audit of existing practice in 2008/2009, a new guideline for the prescribing, monitoring and dose adjustment of vancomycin was introduced in PICU in August 2009. The aim of this study was to assess the impact of the guideline on achieving therapeutic drug levels.
Methods Prescription and laboratory data for patients receiving vancomycin was collected and analysed for a 6 month period following guideline introduction. This data was compared with results obtained from the previous audit.
Results Before guidelines were introduced the 2008/2009 audit showed target trough levels of 10–15 mg/l were achieved in 7% of initial levels taken, 23% of levels overall and 28% of levels following final dose adjustment. 49% of final levels were between 8–18 mg/l. 15 mg/kg three time a day was prescribed for most patients with normal renal function. Prolonged periods of subtherapeutic levels were common. Inadequate dose adjustment and delays for levels to be processed contributed to the problem. Insufficient attention was given to adjusting doses in patients with renal impairment and monitoring was variable.
Following guideline introduction the 2009/2010 audit showed target trough levels of 10–15 mg/l were achieved in 17% of initial levels taken, 34% of levels overall and 56% of levels following final dose adjustment. 82% of final levels were between 8–18 mg/l.
The guidelines split initial dosing recommendations into four categories according to known or anticipated renal function and introduced a higher initial dose of 20 mg/kg three time a day for children with normal renal function. 69% of patients were initially dosed according to the guidelines.
Conclusion Guidelines have improved the quality of vancomycin prescribing on the Unit and the percentage of target levels achieved has significantly increased.
The increased initial starting dose of 20 mg/kg three time a day for children with normal renal function has been extended to all children in the Trust.4 Minor amendments have been made to the guidelines. It is recommended that the guidelines are adopted by all Child Health wards to provide the same guidance on prescribing, monitoring and dose adjustment.