Lab Test

Sirolimus Level

Rapamycin, Rapamune

Test Codes

Antrim #19161, EPIC: LAB5417, SOFT: SIROL



Specimen Collection Criteria

Collect: One Lavender-top EDTA tube. (Minimum Whole Blood: 2.0 mL)

Do not use Serum Separator Tubes.

Time of Collection: Trough, just prior to next dose.

Physician Office/Draw Specimen Preparation

Do not centrifuge. Maintain whole blood in original collection tube at room temperature (20-26°C or 68-78.8°F) prior to transport.

Preparation for Courier Transport

Transport: Whole blood in original collection tube at room temperature (20-26°C or 68-78.8°F). (Minimum: 2.0 mL)

Rejection Criteria

  • Serum Separator (SST) tubes.
  • Serum or plasma specimens. 

In-Lab Processing

Do not centrifuge specimen. Deliver immediately to the appropriate testing station.


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 3 months

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 3 days
Frozen (-20°C/-4°F or below): 2 weeks 


Royal Oak Toxicology Laboratory


Sunday – Saturday. Specimens must be received prior to 1:00 p.m. to be tested the same day.

Reference Range

Trough Therapeutic Concentration: 5.0-15.0 ng/mL.
Critical Value: Greater than 30 ng/mL.

Test Methodology

Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS).

This test was developed and its performance characteristics determined by Beaumont Health. It has not been cleared or approved by the FDA. The Laboratory is regulated under CLIA as qualified to perform high-complexity testing. This test is used for clinical purposes and should not be regarded as investigational or for research.


The therapeutic range for Sirolimus assumes sampling just prior to the next dose in renal transplant patients. The presence of co-medications, time after transplantation, immunologic setting (presence or absence of acute or chronic rejection and degree of HLA match) and the type of organ transplantation may necessitate a modification of therapeutic targets.

Clinical Utility

Sirolimus (Rapamycin, Rapamune) is a macrolide antibiotic used to suppress natural rejection of autologous organ grafts. Sirolimus can cause hyperlipidemia and influence hematological indicators, particularly when administered at high dose or maintained at high blood concentration. Blood concentration measurements of Rapamycin are useful to guide dosage adjustments to achieve optimal immunosuppression while minimizing toxicity. The trough specimen represents the minimum concentration experienced just before the next dose.

CPT Codes

LOINC: 29247-4


Last Updated


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