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HelpTest Code LABFENTX Fentanyl with Metabolite Confirmation, Chain of Custody, Random, Urine
Additional Codes
| Test Name in EPIC | EPIC Test Code | Mnemonic | Mayo Test ID |
|---|---|---|---|
|
FENTANYL WITH METABOLITE CONFIRMATION, URINE (CHAIN OF CUSTODY) |
LABFENTX | FENTX | FENTX |
Useful For
Detection and confirmation of illicit drug use involving fentanyl
Chain of custody is required whenever the results of testing could be used in a court of law. Its purpose is to protect the rights of the individual contributing the specimen by demonstrating that it was under the control of personnel involved with testing the specimen at all times; this control implies that the opportunity for specimen tampering would be limited.
Additional Tests
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| COCH | Chain of Custody Processing | No | Yes |
| ADLTX | Adulterants Survey, CoC, U | Yes | Yes |
Testing Algorithm
Adulterants testing will be performed on all chain of custody urine samples as per regulatory requirements.
Reporting Name
Fentanyl w/metabolite Conf, CoC, USpecimen Type
UrineOrdering Guidance
Specimen Required
Container/Tube: Chain of Custody Kit (T282) containing the specimen containers, seals, and documentation required.
Specimen Volume: 5 mL
Collection Instructions: Collect random urine specimen in the container provided, seal, and submit with the associated documentation to satisfy the legal requirements for chain-of-custody testing.
Additional Information: Submitting less than 5 mL will compromise the ability to perform all necessary testing.
Specimen Minimum Volume
2.1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days | ||
| Ambient | 21 days |
Reject Due To
| Gross hemolysis | OK |
| Gross icterus | Reject |
Clinical Information
Fentanyl is an extremely fast-acting synthetic opioid related to the phenylpiperidines.(1,2) It is available in injectable as well as transdermal formulations.(1) The analgesic effects of fentanyl are similar to those of morphine and other opioids(1): it interacts predominantly with the opioid mu-receptor. These mu-binding sites are discretely distributed in the human brain, spinal cord, and other tissue.(1,3)
Fentanyl is approximately 80% to 85% protein bound. In plasma, the protein binding capacity of fentanyl decreases with increasing ionization of the drug. Alterations in pH may affect its distribution between plasma and the central nervous system (CNS). The average volume of distribution for fentanyl is 6 L/kg (range 3-8).(3,4)
In humans, the drug appears to be metabolized primarily by oxidative N-dealkylation to norfentanyl and other inactive metabolites that do not contribute materially to the observed activity of the drug. Within 72 hours of intravenous (IV) administration, approximately 75% of the dose is excreted in urine, mostly as metabolites with less than 10% representing unchanged drug.(3,4)
The mean elimination half-life is(1-3):
-IV: 2 to 4 hours
-Iontophoretic transdermal system (Ionsys) terminal half-life: 16 hours
-Transdermal patch: 17 hours (13-22 hours; half-life is influenced by absorption rate)
-Transmucosal:
-Lozenge: 7 hours
-Buccal tablet
-100 mcg to 200 mcg: 3 to 4 hours
-400 mcg to 800 mcg: 11 to 12 hours
In clinical settings, fentanyl exerts its principal pharmacologic effects on the CNS. In addition to analgesia, alterations in mood (euphoria, dysphoria) and drowsiness commonly occur.(1,3) Because the biological effects of fentanyl are similar to those of heroin and other opioids, fentanyl has become a popular drug of abuse.
Chain of custody is a record of the disposition of a specimen to document each individual who collected, handled, and performed the analysis. When a specimen is submitted in this manner, analysis will be performed in such a way that it will withstand regular court scrutiny.
Interpretation
The presence of fentanyl above 0.20 ng/mL or norfentanyl above 1.0 ng/mL is a strong indicator that the patient has used fentanyl.
Cautions
Urine concentrations do not correlate well to serum drug levels. For therapeutic drug management, monitor serum levels.
Very high concentrations of butyl fentanyl (>5 mcg/mL) and acetyl fentanyl (>10 mcg/mL) can potentially interfere and cause a low positive (<0.5 ng/mL) fentanyl concentration, but no interference is noted with norfentanyl.
Method Description
This screen is a homogeneous enzyme immunoassay technique. The immunoassay will be performed semiquantitatively. The immunoassay method is based on competition between free drug in the urine sample, and a drug labeled with the enzyme glucose-6-phosphate dehydrogenase for a fixed amount of specific antibody binding sites. Active enzyme converts nicotinamide adenine dinucleotide (NAD+) to NADH, which results in an absorbance change that can be measured spectrophotometrically at 340nm.(Package insert: Fentanyl Enzyme Immunoassay. Immunalysis Corporation; 10/2016)
The received urine sample is centrifuged, diluted, mixed with internal standard and ammonium hydroxide, and vortexed briefly. It is then extracted using supported liquid extraction, and the extract analyzed by an in-house developed liquid chromatography tandem mass spectrometry method.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
4 to 7 daysSpecimen Retention Time
14 daysPerforming 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
80354
G0480 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| FENTX | Fentanyl w/metabolite Conf, CoC, U | 67822-7 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 36653 | Fentanyl Immunoassay Screen | 59673-4 |
| 36191 | Fentanyl by LC-MS/MS | 58381-5 |
| 36190 | Norfentanyl by LC-MS/MS | 58383-1 |
| 36192 | Fentanyl Interpretation | 69050-3 |
| 36193 | Chain of Custody | 77202-0 |
Reference Values
Negative
Cutoff concentrations:
Immunoassay screen
<2 ng/mL
Fentanyl by liquid chromatography-tandem mass spectrometry (LC-MS/MS)
0.2 ng/mL
Norfentanyl by LC-MS/MS
1.0 ng/mL
Method Name
Immunoassay/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
Forms
1. Chain of Custody Request is included in the Chain-of-Custody Kit (T282).
2. If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.