Test Code FENTS Fentanyl, Serum
Reporting Name
Fentanyl and Metabolites, SUseful For
Monitoring fentanyl therapy
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
Serum RedSpecimen 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 Minimum Volume
1.25 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum Red | Frozen (preferred) | 28 days | |
Refrigerated | 14 days | ||
Ambient | 72 hours |
Reference Values
Not applicable
Day(s) Performed
Tuesday, Thursday
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
80354
G0480 (if appropriate)
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 |
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.
Clinical Reference
1. Gutstein HB, Akil H. Opioid analgesics. In: Brunton LL, Lazo JS, Parker KL, eds. Goodman and Gilman's: The Pharmacological Basis of Therapeutics. 11th ed. McGraw-Hill Companies; 2006:chap 21
2. Kerrigan S, Goldberger BA. Opioids. In: Levine B, eds. Principles of Forensic Toxicology. 2nd ed. AACC Press; 2003:187-205
3. DURAGESIC (fentanyl transdermal system). Package insert: Janssen Pharmaceutica Products, LP; 2006
4. Baselt RC. Disposition of Toxic Drugs and Chemicals in Man. 12th ed. Biomedical Publications; 2020
5. Yaksh T, Wallace M. Opioids, Analgesia, and Pain Management. In: Brunton LL, Hilal-Dandan R, Knollmann BC, eds. Goodman and Gilman's: The Pharmacological Basis of Therapeutics, 13th ed. McGraw-Hill Education; 2017
6. Langman LJ, Bechtel LK, Holstege CP. Clinical toxicology. In: Rifai N, Chiu RWK, Young I, Burnham CAD, Wittwer CT, eds. Tietz Textbook of Laboratory Medicine. 7th ed. Elsevier; 2023:chap 43
7. Fentanyl. In: Merative Micromedex (electronic version). Merative US 2024. Accessed July 15, 2024. Available at www.micromedexsolutions.com
Report Available
2 to 7 daysMethod Name
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.