Test Code FENTS Fentanyl, Serum
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.
Useful For
Monitoring fentanyl therapy
Method Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Reporting Name
Fentanyl and Metabolites, SSpecimen Type
Serum RedSpecimen 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
Day(s) Performed
Tuesday, Thursday
Report Available
2 to 7 daysPerforming Laboratory

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.