Sign in →

Test Code FENTS Fentanyl, Serum

Reporting Name

Fentanyl and Metabolites, S

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Monitoring fentanyl therapy

Method Name

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


Specimen Required


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Red top (Serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 2.3 mL

Collection Instructions: Within 2 hours of collection, centrifuge and aliquot serum into a plastic vial.


Specimen Type

Serum Red

Specimen Minimum Volume

1.25 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Red Frozen (preferred) 28 days
  Refrigerated  14 days
  Ambient  72 hours

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Reference Values

Fentanyl:

Average serum fentanyl concentrations 24 hours after application of transdermal patch:

25 mcg/hour: 0.3-1.2 ng/mL

50 mcg/hour: 0.6-1.8 ng/mL

75 mcg/hour: 1.1-2.6 ng/mL

100 mcg/hour: 1.9-3.8 ng/mL

(Baselt RC. Disposition of Toxic Drugs and Chemical in Man. 12th ed. Biomedical Publications; 2020)

 

Norfentanyl:

Reference range: Not established

 

Cutoff concentrations by liquid chromatography tandem mass spectrometry:

Fentanyl: 0.05 ng/mL

Norfentanyl: 0.25 ng/mL

Interpretation

Both fentanyl and norfentanyl are reported.

 

Tolerant individuals may require many-fold increases in dose to achieve the same level of analgesia, which can greatly complicate interpretation of therapeutic drug monitoring results and establishment of a therapeutic window.

 

Concentration at which toxicity occurs varies and should be interpreted in light of clinical situation.

Day(s) Performed

Tuesday, Thursday

Report Available

2 to 7 days

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

G0480

80354 (if appropriate for select payers)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FENTS Fentanyl and Metabolites, S 81275-0

 

Result ID Test Result Name Result LOINC Value
31829 Norfentanyl 11074-2
31830 Fentanyl 3636-8
31832 Chain of Custody 77202-0

Forms

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