Vancomycin Dosing for Serious MRSA Infections: A Non-inferiority Randomized Trial of Trough Level Versus AUC/MIC (TAUC)

January 21, 2026 updated by: Anthony Bai
Intravenous vancomycin is considered first line therapy for serious methicillin-resistant Staphylococcus aureus (MRSA) infections including bacteremia, central nervous system infection, pneumonia, pleural space infection, bone or joint infection, prosthetic joint infection and deep abscesses. The effectiveness and toxicity of vancomycin depend on its dosing and chosen target. The most recent guidelines suggest targeting area under the curve over 24 hours over minimum inhibitory concentration (AUC/MIC) of 400 to 600. Implementation of AUC/MIC requires Bayesian software that can be variable, costly, complicated and time consuming. Ideally, AUC/MIC dosing would also require susceptibility testing by broth microdilution, which is not commonly done. It is recommended to target AUC of 400 to 600 assuming a MIC of 1ug/mL when MIC by broth microdilution is not known. Targeting a trough level of 10 to 15mg/L may be a reasonable and more practical alternative without compromising effectiveness. We will be conducting a randomized controlled non-inferiority trial to compare intravenous vancomycin dosing strategy targeting a trough level of 10 to 15mg/L versus AUC of 400 to 600 assuming a MIC of 1ug/mL by broth microdilution for serious MRSA infections. The primary outcome will be treatment failure, which is a composite of mortality and microbiologic failure at 90 days. We hypothesize that targeting a trough level of 10 to 15mg/L is non-inferior to targeting a AUC of 400 to 600 in terms of treatment failure. The criterion for non-inferiority is that a two-sided 95% confidence interval for difference in risk of treatment failure will lie within the non-inferiority margin of 10%.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

700

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Ontario
      • Hamilton, Ontario, Canada, L8N 4A6
        • Recruiting
        • St. Joseph's Healthcare Hamilton
        • Contact:
      • Hamilton, Ontario, Canada, L8L 2X2
        • Recruiting
        • Hamilton Health Sciences
        • Contact:
      • Kingston, Ontario, Canada, K7L 2V7
        • Recruiting
        • Kingston Health Sciences Centre
        • Contact:
    • Quebec
      • Montreal, Quebec, Canada, H3H 2R9
        • Recruiting
        • McGill University Health Centre
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adult patients with serious MRSA infections based on culture results including bacteremia, pneumonia, pleural space infection, central nervous system infection, bone infection, septic arthritis, prosthetic joint infection, and deep abscess
  • Enrolment within 4 days from date of MRSA culture collection
  • Patient either currently not on vancomycin or has received vancomycin for 4 days or less

Exclusion Criteria:

  • Vancomycin minimum inhibitory concentration (MIC) ≥2ug/mL
  • Patient is palliative or expected to die in the next 48 hours, or requires critical care resources but will not receive it due to advanced care directives
  • History of type 1 hypersensitivity reaction to vancomycin
  • Patients on intermittent hemodialysis or peritoneal dialysis

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Vancomycin targeting trough of 10 to 15mg/L

If the patient has not received intravenous vancomycin yet, a loading dose of 25mg/kg (maximum 2g) will be given if the patient is severely ill at the discretion of the physician and pharmacist. The initial dose is 15mg/kg with a maximum dose of 2g. The frequency would be based on creatinine clearance (CrCl) as per the Cockcroft-Gault equation: Q8H if CrCl is >100mL/min, Q12H if CrCl is 50-100mL/min, Q24H if CrCl is 30- 49mL/min, and Q48H if CrCl is <30mL/min. Pharmacists can change the initial dose at their own discretion.

Trough level will be done 30 minutes before the 4th dose. For Q48H dosing, a trough level will be done before the second dose. Vancomycin dosing will be adjusted to target trough level of 10 to 15mg/L. If not at target, the pharmacist will adjust the dose based on an assumption of linear pharmacokinetics. Trough will be remeasured before the fourth dose of the new regimen.

Administration as outlined
Active Comparator: Vancomycin targeting AUC of 400 to 600

The initial intravenous vancomycin dosing is the same as described above for the trough group.

The AUC target will be 400 to 600, which assumes a MIC of 1ug/mL by broth microdilution.

After the first non-loading dose of vancomycin, patients will have vancomycin level 30 minutes before the next dose. As per the pharmacist's discretion, patient may have an additional vancomycin level one hour after infusion of vancomycin for more accurate estimates. A pharmacist will use a Bayesian software to estimate the AUC and the optimal dose.

Administration as outlined

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Treatment failure
Time Frame: 90 days
Treatment failure is defined as death due to any cause or microbiologic failure based on demonstration of MRSA on repeated culture from the original site or another sterile site more than 1 week from randomization. Treatment failure will be determined by an independent committee of physicians after reviewing the clinical, laboratory and microbiologic data.
90 days

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Major adverse kidney events
Time Frame: 90 days
New and persistent renal-replacement therapy, or serum creatinine that is 200% or more than the baseline value during the follow-up period
90 days
Vancomycin associated nephrotoxicity
Time Frame: 90 days
Increase in serum creatinine by ≥26.4mmol/L or ≥50% since starting vancomycin when compared to baseline
90 days
Renal replacement therapy
Time Frame: 90 days
Need for initiation of renal replacement therapy at any time during follow-up
90 days
Day 3 AUC
Time Frame: 3 days
AUC as calculated using Bayesian modeling on day 3 from randomization
3 days
Vancomycin cost
Time Frame: 90 days
Direct cost of vancomycin monitoring and dosing from perspective of hospital system
90 days
Time to target
Time Frame: 90 days
Time in days to reach target level (trough of 10 to 15mg/L in the intervention group and AUC/MIC of 400 to 600 in the comparison group)
90 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Collaborators

Investigators

  • Principal Investigator: Anthony D Bai, MD, Queen's University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 20, 2023

Primary Completion (Estimated)

July 1, 2029

Study Completion (Estimated)

October 1, 2029

Study Registration Dates

First Submitted

March 8, 2021

First Submitted That Met QC Criteria

March 10, 2021

First Posted (Actual)

March 11, 2021

Study Record Updates

Last Update Posted (Actual)

January 23, 2026

Last Update Submitted That Met QC Criteria

January 21, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • 13327

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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