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Test Code LABFDXM Dexamethasone, Serum

Additional Codes

Test Name in EPIC

EPIC Test Code

Mnemonic

Mayo Test ID
Dexamethasone LABFDXM DEXA DEXA

 


Ordering Guidance


To detect the metabolite of fluticasone or Flonase, order 17BFP / Fluticasone 17-Beta-Carboxylic Acid, Random, Urine.

 

For synthetic glucocorticoid analyte screen, order SGSS / Synthetic Glucocorticoid Screen, Serum.



Specimen Required


Collection Container/Tube:

Preferred: Red top

Acceptable: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 2 mL

Collection Instructions:

1. Draw blood between 7:30 a.m. and 9:00 a.m. the morning following an evening dose.

2. Centrifuge and aliquot serum into plastic vial within one hour of collection and freeze immediately.


Useful For

Confirming the presence of dexamethasone in serum

 

Confirming the cause of secondary adrenal insufficiency

 

This test is not useful as the sole basis for a diagnosis or treatment decisions.

Method Name

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

Reporting Name

Dexamethasone, S

Specimen Type

Serum

Specimen Minimum Volume

0.6 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 28 days
  Refrigerated  7 days
  Ambient  72 hours

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Clinical Information

Synthetic glucocorticoids are widely used and have an important clinical utility both as antiinflammatory and immunosuppressive agents. The medical use of these agents, as well as their surreptitious use, can sometimes lead to a confusing clinical presentation. Patients exposed to these steroids may present with clinical features of Cushing syndrome but with suppressed cortisol levels and evidence of hypothalamus-pituitary-adrenal axis suppression.

Reference Values

Baseline: <30 ng/dL

8:00 a.m. following 1 mg Dexamethasone, previous evening: >100 ng/dL

8:00 a.m. following 8 mg Dexamethasone, (4 x 2 mg doses) previous day: >800 ng/dL

Interpretation

This test will screen for, and quantitate if present, the synthetic glucocorticoid, dexamethasone.

 

The presence of this synthetic glucocorticoid in serum indicates the current or recent use of this compound.

Cautions

Lack of detection does not preclude use of dexamethasone because adrenal suppression may persist for some time after the exogenous steroid is discontinued.

Method Description

Dexamethasone is extracted from serum and measured by liquid chromatography (high-resolution accurate-mass) mass spectrometry.(Unpublished Mayo method)

Day(s) Performed

Tuesday, Thursday

Report Available

2 to 6 days

Specimen Retention Time

3 months

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

80299

LOINC Code Information

Test ID Test Order Name Order LOINC Value
DEXA Dexamethasone, S 14062-4

 

Result ID Test Result Name Result LOINC Value
609439 Dexamethasone, S 14062-4

Forms

If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.