Standard of care dosing of vancomycin in young infants is based on weight (eg. 15 mg/kg/dose). There is evidence that many young infants who are prescribed vancomycin using this calculation will not have enough vancomycin in the blood at steady state to treat an infection effectively. In this study a dosing calculator will be used to generate each participant's dose with the aim to improve the number of participant's who achieve the target vancomycin level (10 - 20 mg/L) at steady state. The dosing calculator is based on a pharmacokinetic/pharmacodynamic model of vancomycin which was built from prospective data. The participant's weight, post-menstrual age, creatinine and target vancomycin level will be entered into the dosing calculator (available on a web application), and the calculator will provide the dosing regimen for that participant. The participant will have the vancomycin level checked at 24-48 hours to assess if the target level has been achieved.
This study is 'part 1' of the study protocol (version 4.0) as approved under HREC reference number HREC/51942/RCHM-2019. This protocol also includes a second study, 'part 2', which will be registered with clinicaltrials.gov separately. Part 2 will assess the use of early drug monitoring and early dose adjustment to achieve the target vancomycin level in the blood at steady state. Part 1 of this protocol will be completed before part 2 begins recruitment. Part 1 and part 2 are two separate studies and the results of each part will not be compared to one another. However, each part will be compared to a retrospective control arm - infants from the VANC randomized controlled trial (NCT02210169) who received standard intermittent infusion of vancomycin dosing (as per British National Formulary for children. 15mg/kg/dose) and standard therapeutic drug monitoring.