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Test Code KETAU Ketamine and Metabolite Confirmation, Urine

Reporting Name

Ketamine Confirmation, U

Useful For

Detection and confirmation of ketamine use

Method Name

Gas Chromatography-Mass Spectrometry (GC-MS)

Performing Laboratory

Mayo Medical Laboratories in Rochester

Specimen Type


Advisory Information

For chain-of-custody testing, order KETAX / Ketamine and Metabolite Confirmation, Chain of Custody, Urine

Additional Testing Requirements

If urine creatinine is required or adulteration of the sample is suspected, also order ADULT / Adulterants Survey, Urine.

Specimen Required

Supplies: Urine Container, 60 mL (T313)

Collection Container/Tube: Plastic, 60-mL urine container (T313)

Specimen Volume: 20 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.

Additional Information:

1. No specimen substitutions.

2. No STATS are accepted for this procedure.

Specimen Minimum Volume

5 mL

Specimen Stability Information

Specimen Type Temperature Time
Urine Refrigerated (preferred) 14 days
  Frozen  14 days
  Ambient  72 hours

Reject Due To


Mild OK: Gross OK




Mild OK: Gross OK



Reference Values


Day(s) and Time(s) Performed

Tuesday, Thursday

CPT Code Information


G0480 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
KETAU Ketamine Confirmation, U In Process


Result ID Test Result Name Result LOINC Value
31128 Norketamine 18322-8
89443 Ketamine Confirmation, U 20537-7
29903 Ketamine Interpretation 69050-3
29904 Chain of Custody No LOINC Needed

Analytic Time

2 days


No significant cautionary statements

Method Description

Phencyclidine, norketamine, and ketamine, along with the deuterated internal standards, are extracted from buffered urine using solid-phase extraction techniques. The eluent from the column is dried and then analyzed by gas chromatography-mass spectrometry.(Unpublished Mayo method)


The presence of ketamine or norketamine levels above 25 ng/mL is a strong indicator that the patient has used ketamine.

Specimen Retention Time

2 weeks

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

Clinical Information

Ketamine has been used in the United States as an anesthetic induction agent since 1972. The drug acts by noncompetitive antagonism of the N-methyl-D-aspartate (NMDA)-type glutamate receptors.(1,2) Ketamine has become a popular street drug because of its hallucinogenic effects.(3)


Ketamine has a half-life of 3 to 4 hours, and is metabolized to norketamine.(3) The effects from ketamine last from 1 to 5 hours, and ketamine and norketamine can be detected in the urine for a period of 1 to 2 days following use.(4)