Related Experiment Video
Updated: Aug 7, 2026

Nanomechanics of Drug-target Interactions and Antibacterial Resistance Detection
Published on: October 25, 2013
Vancomycin-binding characteristics in patients with serious infections
1Department of Pediatrics, Eastern Virginia Medical School, Norfolk 23510, USA.
Study Objective:
To examine the extent, variability, and factors affecting vancomycin protein binding.
Design:
Prospective, open-label, cohort study.
Setting:
A general hospital.
Patients:
Forty-four adults [mean (+/- SD) age 50.9 +/- 17.1 yrs, range 16.8-92.0 yrs] with serious infections.
Interventions:
Unbound (Vu) and total (Vtot) vancomycin concentrations were determined by fluorescence polarization immunoassay. A statistical analysis model used the maximum likelihood method to evaluate the association between several important variables and log Vu while controlling for log Vtot effects.
Measurements And Main Results:
The mean fraction percentage of unbound vancomycin was 79.5 +/- 6.0% (range 53.0-96.3%). While controlling for Vtot the total variability of Vu was 8.3%, suggesting that vancomycin binding is relatively constant in sick adults. We were able to demonstrate a significant statistical interaction effect between gender and globulin protein concentration on Vu (p = 0.022). Globulin protein concentration in men was negatively associated with Vu (p = 0.0009), but there was no association in women (p = 0.645). Age, race, peak-trough association, serum creatinine, serum albumin, serum prealbumin, and hemodialysis were not significantly associated with log Vu in the statistical model.
Conclusion:
Compared with earlier studies in healthy adults, vancomycin binding appears to be decreased during acute illness, and intrapatient and interpatient variability are relatively small. Unbound vancomycin concentration appears to be gender dependent.
Related Concept Videos
Factors Affecting Protein-Drug Binding: Drug-Related Factors
One crucial factor in drug-protein binding is the drug's lipophilicity or its affinity for fat. More lipophilic drugs tend to have higher binding extents. For example, highly lipophilic drugs like cloxacillin exhibit substantial protein binding, with as much as 95% of the drug binding to proteins. In contrast,...
Hepatic Drug Clearance: Effect of Protein Binding
For low-extraction-ratio drugs that are less than 80% protein-bound, minor changes in protein binding...
Estimation of k and VD of Aminoglycosides
Inhibitors of Gram-positive Cell Wall Synthesis
Inhibitors of Bacterial Protein Synthesis
Clinical Significance of Antibiotic Resistance

