Platform
Company
Drug Monitoring
Review status
Currently under review
Pending specialist review and validation.
This test measures the amount of vancomycin in your blood just before your next scheduled dose. It is called a trough level or pre-dose level, and it helps your care team understand how much drug remains in your system at the lowest point between doses.
Vancomycin is an antibiotic used to treat serious infections. Because people handle the drug differently, this blood test is part of therapeutic drug monitoring, which helps tailor dosing to you for both effectiveness and safety.
Getting the right amount of vancomycin into your bloodstream is important. If the level is too low, the antibiotic may not control the infection well. If it is too high, the chance of side effects, including kidney problems or hearing-related symptoms, can increase. Your clinician may order this test early in treatment, after dose changes, or when your condition changes.
The test is especially important if you have kidney disease, are critically ill, are receiving dialysis, or are taking other medicines that can affect the kidneys. It guides your team in choosing a dose and dosing schedule that fits your situation and infection.
Your clinician or pharmacist will compare your result with a goal selected for your infection and overall health. If your level is lower than expected, they may adjust the dose or shorten the time between doses. If it is higher than expected, they may reduce the dose, extend the time between doses, or delay the next dose. Follow-up levels are often checked to confirm that any changes are working for you.
Make sure the sample was drawn right before your next dose and tell your team the exact time of your last dose, since timing can change how the result is interpreted. Do not change your dose on your own. If you notice symptoms such as decreased urine, ringing in the ears, dizziness, rash, or flushing, contact your care team promptly. They may repeat the test, check kidney function, or adjust your treatment plan.
Reference intervals vary by laboratory, analyzer, methodology, population, and units. The ranges shown here are for education only. Always interpret your results against the reference interval printed on your own lab report.
For a trough level, the sample should be collected immediately before the next scheduled dose. Samples taken after an infusion or far from the next dose can misrepresent your lowest level.
Your kidneys clear vancomycin from the body. Reduced kidney function or sudden changes in kidney status can raise levels and increase the risk of side effects, requiring closer monitoring.
Dialysis can remove vancomycin, and critical illness can alter fluid balance and drug handling. These situations often need customized dosing and more frequent checks.
Medicines that affect the kidneys, such as certain antibiotics, diuretics, or contrast dye, can change vancomycin handling and side effect risk. Always share an up-to-date medication list.
Large body size, obesity, burns, or significant swelling can change how vancomycin distributes in the body, influencing the dose needed to achieve a therapeutic level.
Drawing blood from the same line used to infuse vancomycin without proper technique can contaminate the sample and falsely elevate the level. Peripheral draws are preferred when possible.
Missed, late, or extra doses change the trough level. Tell your care team if your dosing schedule was different than planned so your result can be interpreted correctly.
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