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25562 Tacrolimus

Tacrolimus
Test Code: TACRO
Synonyms/Keywords
​FK506, Prograf​
Useful For
​Monitoring whole blood tacrolimus concentration during therapy, particularly in individuals coadministered CYP3A4 substrates, inhibitors, or inducers.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)​
​Whole blood ​EDTA Lavender Top Tube (LTT) ​3 mL ​1 mL 250 uL​
Collection Processing Instructions
​1. Draw blood immediately before a schedule dose.
2. Do not centrifuge.
3. Send specimen in original tube.
 
Additional Information:
1. Therapeutic range applies to trough specimens drawn immediately prior to a.m. dose.
2. If sirolimus analysis is desired, draw and send another tube.  Tests can not be combined.
Specimen Stability Information
Specimen Type Temperature Time
​Whole blood ​ ​ ​Refrigerated (preferred) ​14 days
​Ambient ​14 days
​Frozen ​14 days
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield
​Monday through Friday
(Prior to noon)
​1 day Liquid Chromatography/Tandem Mass Spectrometry (LCMS/MS) using Multiple Reaction Monitoring
Test Information
This test was developed and its performance characteristics determined by Marshfield Labs.  It has not been cleared or approved by the US Food and Drug Administration.  This test is used for clinical purposes.  It should not be regarded as investigational or for research.
Reference Range Information
Performing Location Reference Range
​Marshfield
​5.0-15.0 ng/mL
Results are reported with a quantitative LC-MS/MS result
Interpretation

​Most individuals display optimal response to tacrolimus with trough whole blood levels of 5.0 ng/mL to 15.0 ng/mL. Preferred therapeutic ranges may vary by transplant type, protocol, and comedications.

Therapeutic ranges are based on samples drawn at trough (ie, immediately before a scheduled dose). Blood drawn at other times will yield higher results.

Therapeutic Range:
Kidney Transplant
0-3 months post-transplant: 7.0-20.0 ng/mL
3 months and older: 5.0-15.0 ng/mL

Heart Transplant
0-3 months post-transplant: 10.0-20.0 ng/mL
3 months and older: 5.0-15.0 ng/mL

Liver Transplant
1-12 months post-transplant: 5.0-20.0 ng/mL

Toxic Value: Greater than 25.0 ng/mL

The assay is specific for tacrolimus; it does not cross-react with cyclosporine, cyclosporine metabolites, sirolimus, sirolimus metabolites, or tacrolimus metabolites. Results by liquid chromatography with detection by tandem mass spectrometry are approximately 30% less than by immunoassay.

Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​80197
Classification
This test was developed and its performance characteristics determined by Marshfield Labs.  It has not been cleared or approved by the US Food and Drug Administration.  This test is used for clinical purposes.  It should not be regarded as investigational or for research.
Synonyms/Keywords
​FK506, Prograf​
Ordering Applications
Ordering Application Description
COM​​ ​Tacrolimus
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen Type Preferred Container/Tube Acceptable Container/Tube Specimen Volume Specimen Minimum Volume
(allows for 1 repeat)
Pediatric Minimum Volume
(no repeat)​
​Whole blood ​EDTA Lavender Top Tube (LTT) ​3 mL ​1 mL 250 uL​
Collection Processing
​1. Draw blood immediately before a schedule dose.
2. Do not centrifuge.
3. Send specimen in original tube.
 
Additional Information:
1. Therapeutic range applies to trough specimens drawn immediately prior to a.m. dose.
2. If sirolimus analysis is desired, draw and send another tube.  Tests can not be combined.
Specimen Stability Information
Specimen Type Temperature Time
​Whole blood ​ ​ ​Refrigerated (preferred) ​14 days
​Ambient ​14 days
​Frozen ​14 days
Useful For
​Monitoring whole blood tacrolimus concentration during therapy, particularly in individuals coadministered CYP3A4 substrates, inhibitors, or inducers.
Reference Range Information
Performing Location Reference Range
​Marshfield
​5.0-15.0 ng/mL
Results are reported with a quantitative LC-MS/MS result
Interpretation

​Most individuals display optimal response to tacrolimus with trough whole blood levels of 5.0 ng/mL to 15.0 ng/mL. Preferred therapeutic ranges may vary by transplant type, protocol, and comedications.

Therapeutic ranges are based on samples drawn at trough (ie, immediately before a scheduled dose). Blood drawn at other times will yield higher results.

Therapeutic Range:
Kidney Transplant
0-3 months post-transplant: 7.0-20.0 ng/mL
3 months and older: 5.0-15.0 ng/mL

Heart Transplant
0-3 months post-transplant: 10.0-20.0 ng/mL
3 months and older: 5.0-15.0 ng/mL

Liver Transplant
1-12 months post-transplant: 5.0-20.0 ng/mL

Toxic Value: Greater than 25.0 ng/mL

The assay is specific for tacrolimus; it does not cross-react with cyclosporine, cyclosporine metabolites, sirolimus, sirolimus metabolites, or tacrolimus metabolites. Results by liquid chromatography with detection by tandem mass spectrometry are approximately 30% less than by immunoassay.

For more information visit:
Performing Laboratory Information
Performing Location Day(s) Test Performed Analytical Time Methodology/Instrumentation
​Marshfield
​Monday through Friday
(Prior to noon)
​1 day Liquid Chromatography/Tandem Mass Spectrometry (LCMS/MS) using Multiple Reaction Monitoring
For billing questions, see Contacts
Outreach CPTs
CPT Modifier
(if needed)
Quantity Description Comments
​80197
Classification
This test was developed and its performance characteristics determined by Marshfield Labs.  It has not been cleared or approved by the US Food and Drug Administration.  This test is used for clinical purposes.  It should not be regarded as investigational or for research.
For most current information refer to the Marshfield Laboratory online reference manual.