Study of Obese Patients Comparing Two Vancomycin Loading Dose Regimens

Single-Center Prospective Study of Obese Patients Comparing Two Vancomycin Loading Dose Regimens

Obesity alters the movement through the body of several antibiotics, including vancomycin. Based on literature to date, total body weight should be used to determine dosages and shorter dosing intervals may be needed. However, hospitals have different approaches to managing vancomycin in this patient population. The most common example is not exceeding a dose of 2,000mg of vancomycin at one time in these patients. However, some institutions including the Charleston Area Medical Center do not have a set maximum one time dose. To date, a study has not been done comparing two different dosing regimens in obese patients to determine if having a maximum dose cap is beneficial.

This research study is attempting to add to the limited existing body of literature regarding vancomycin dosing in obese patients. The investigators hypothesize that optimizing the initial or loading vancomycin dose that obese patients receive will decrease the time to target concentrations. For this study, obese adult patients will be randomized to receive either 1) a loading dose of 20 mg/kg with a maximum dose up to 2,000mg OR 2) a loading dose of 20 mg/kg with a maximum dose of up to 4,000mg. The study's primary aim is to determine differences in the time needed to achieve target vancomycin concentrations and the occurrence of adverse events.

Study Overview

• Status: Completed
• Conditions: Sepsis; Obesity; Infection
• Intervention / Treatment: Drug: IV vancomycin

• Study Type: Interventional
• Enrollment (Actual): 76
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • West Virginia
    • Charleston, West Virginia, United States, 25304
      • CAMC Health Systems

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 99 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Patients ≥18 years of age who present to the Charleston Area Medical Center-Memorial Hospital Emergency Department
• Weight >100kg
• Infection requiring intravenous vancomycin and admission to Charleston Area Medical Center-Memorial Hospital

Exclusion Criteria:

• Any patient <18 years of age
• Patients on dialysis or with unstable renal function (a change of >0.5 mg/dL in SCr concentration in patients with a SCr of <2 mg/dL or a 20% change in SCr in patients with a SCr of ≥2 mg/dL)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: IV Vancomycin loading dose- higher; IV Vancomycin loading dose: 20 mg/kg with a maximum dose of 4,000mg	Drug: IV vancomycin; IV vancomycin for the treatment of infection. Following the vancomycin loading dose, vancomycin dosing will be at the discretion of the pharmacist and attending physician and will follow standard of care.
Experimental: IV Vancomycin loading dose- lower; IV Vancomycin loading dose: 20 mg/kg with a maximum dose of 2,000mg	Drug: IV vancomycin; IV vancomycin for the treatment of infection. Following the vancomycin loading dose, vancomycin dosing will be at the discretion of the pharmacist and attending physician and will follow standard of care.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time to Attain Therapeutic Vancomycin Concentrations.	Time to attain therapeutic vancomycin concentrations was measured in hours. Therapeutic vancomycin concentrations were set as 15-20 mg/L in patients with serious, documented Gram-positive infections (e.g., endocarditis, meningitis, pneumonia, osteomyelitis), while in patients with a lower risk of Gram-positive infections (e.g., pyelonephritis, skin/tissue structured infections), therapeutic vancomycin concentrations were defined as 10-15 mg/L.	Time Frame: 20 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Reported Adverse Events (AE)	Red Man's syndrome: pruritus and erythematous rash involving the face, neck, and upper torso. Red Man's syndrome is an older term for vancomycin flushing syndrome (VFS). Nephrotoxicity: increase in serum creatinine (SCr) by 0.5 mg/dL or 50% from baseline on two consecutive measurements.	48 hours post initial vancomycin dose
Examine the Pharmacokinetic Parameter of Elimination Rate Constant (ke) Following the Loading Vancomycin Dose	These measurements assessed the elimination rate constant of vancomycin between the two treatment regimens. Two elimination rate constants were assessed: Elimination constant at 7.5-hour trough level and Elimination constant at initial trough level.	12 hours
Intensive Care Unit Length of Stay	The duration of time participants spent in the intensive care unit (ICU) during their hospitalization. This outcome measures the total number of days spent in the ICU, from ICU admission to discharge from ICU.	30 days
Hospital Length of Stay	The total duration of hospitalization, measured from the time of hospital admission to discharge.	60 days
In-hospital Mortality	The percentage of participants that died during their hospital stay. This measure assesses the mortality rate from the time of hospital admission until discharge or death.	60 days

Collaborators and Investigators

• Sponsor: CAMC Health System

Study record dates

Study Major Dates

• Study Start (Actual): August 1, 2016
• Primary Completion (Actual): April 1, 2024
• Study Completion (Actual): April 1, 2024

Study Registration Dates

• First Submitted: May 2, 2016
• First Submitted That Met QC Criteria: May 5, 2016
• First Posted (Estimated): May 6, 2016

Study Record Updates

• Last Update Posted (Actual): November 3, 2026
• Last Update Submitted That Met QC Criteria: October 16, 2026
• Last Verified: October 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Nutrition Disorders; Overnutrition; Body Weight; Systemic Inflammatory Response Syndrome; Inflammation; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Sepsis; Infections; Peptides; Amino Acids, Peptides, and Proteins; Carbohydrates; Glycoconjugates; Glycopeptides; Vancomycin
• Other Study ID Numbers: 15-120

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO