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Test Code FENTU Fentanyl with Metabolite Confirmation, Random, Urine

Reporting Name

Fentanyl w/metabolite Conf, U

Useful For

Detection and confirmation of illicit drug use involving fentanyl

Specimen Type

Urine


Ordering Guidance


For situations where chain of custody is required, a Chain of Custody Kit (T282) is available. For chain-of-custody testing, order FENTX / Fentanyl with Metabolite Confirmation, Chain of Custody, Random, Urine.



Additional Testing Requirements


If urine creatinine is required or adulteration of the sample is suspected, the following test should also be ordered, ADULT / Adulterants Survey, Random, Urine.



Specimen Required


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Clean, plastic urine collection container

Submission Container/Tube: Plastic, 5-mL tube

Specimen Volume: 5 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.

Additional Information:

1. No specimen substitutions.

2. STAT requests are not accepted for this procedure.

3. Submitting less than 5 mL will compromise our 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

Reference Values

Negative

CPT Code Information

80354

G0480 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FENTU Fentanyl w/metabolite Conf, U 67822-7

 

Result ID Test Result Name Result LOINC Value
45530 Fentanyl by LC-MS/MS 58381-5
45531 Norfentanyl by LC-MS/MS 58383-1
45532 Fentanyl Interpretation 69050-3

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 is 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 to 200 mcg: 3 to 4 hours

-400 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.

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.

Reject Due To

Gross hemolysis OK
Gross icterus Reject

Method 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.