UC San Diego

Context

Vancomycin is a medication with potential for significant harm with both overdosing and underdosing. Obesity may affect vancomycin pharmacokinetics and is increasingly common among children.

Objective

We aimed to determine if children with overweight or obesity have increased vancomycin trough concentrations with total body weight (TBW) dosing compared with children with normal weight.

Data sources

We conducted a search of Medline and Medline In-Process & Other Non-Indexed Citations from 1952 (the year vancomycin was discovered) to November 2017.

Study selection

Search terms included vancomycin, body weight, and body composition terms and were limited to children. Studies were reviewed and screened by ≥2 reviewers.

Data extraction

The primary outcome was vancomycin level. Data were extracted by 2 reviewers. We performed quality assessment using the Newcastle-Ottawa quality assessment scale.

Results

We identified 271 records. After abstract and full-text screening, we identified 7 studies for full review. Six of the 7 studies used a matched case-control design, although there was significant variation in study methodology. Four of the 7 studies were included in a meta-analysis, which revealed a small but significant difference in vancomycin trough levels between children with normal weight and children with overweight or obesity when dosed by using TBW (N = 521; mean difference 2.2 U [95% confidence interval: 1.0-3.4]).

Conclusions

High-quality data to guide vancomycin dosing in children with obesity are lacking. More studies evaluating dosing strategies in children with obesity are warranted because using TBW to dose vancomycin may lead to higher vancomycin concentrations and potential toxicity.