The Clinical Validation of a Dried Blood Spot Method for Vancomycin and Creatinine

Study Overview
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Brief Summary
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A widely used antibiotic is vancomycin. To ensure adequate exposure to vancomycin, drug doses are adjusted based on whole-blood concentration measurements, a practice known as therapeutic drug monitoring (TDM). The need for TDM of vancomycin is well established, as described in several national and international guidelines, for dose-optimization in order to achieve successful treatment and to prevent toxicity and reduce microbial resistance. A sampling method for TDM that has become more popular over the recent years is dried blood spotting (DBS). DBS is a design of blood sampling consisting of positioning a drop of capillary blood, preferably taken from the finger, on filter paper. Unlike venous blood sampling (the current gold standard for TDM of vancomycin), DBS seems to have advantages for the patient. The finger prick is less invasive than venipuncture. DBS also enables patients to perform one or multiple finger prick(s) themselves, with the possibility to sample at multiple time points. Due to the fact that vancomycin is nephrotoxic, it would be very efficient and convenient to measure creatinine in the same dried blood spot as the vancomycin. This study is a clinical validation study to validate the DBS assay for vancomycin.

Official Title
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The Clinical Validation of a Dried Blood Spot Method for Vancomycin and Creatinine

Conditions
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Vancomycin

Intervention / Treatment
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* Diagnostic Test: fingerprick


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Clinical patients Aged 18 and over Able to understand written information and able to give informed consent Treated with vancomycin Able and willing to undergo a finger prick for dried blood spot sampling Able and willing to fill in a questionnaire Exclusion Criteria: Unable to draw blood samples for study purposes

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: fingerprick|In addition to the standard venous samples, dried blood spot samples trough a fingerprick will be collected.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To clinically validate the DBS method for vancomycin and creatinine in comparison to venipuncture vancomycin and creatinine analysis |  | 5 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Analyzing the differences in the measured concentrations in the dried blood spot made with blood obtained from venous sampling and capillary sampling. |  | 5 months | 
| Evaluating the need of a correction factor and optimizing the correction factor when measuring the hematocrit in the DBS samples |  | 5 months | 
| To investigate the patients' experience with the DBS method in comparison to venipuncture |  | 5 months |