Ketamine and Metabolite Confirmation, Chain of Custody, Urine
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
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/or norketamine can be detected in the urine for a period of 1 to 2 days following use.(4)
Chain of custody is a record of the disposition of a specimen to document who collected it, who handled it, and who 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.
Detection and confirmation of ketamine use
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.
The presence of ketamine and/or norketamine >25 ng/mL is a strong indicator that the patient has used ketamine.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
No significant cautionary statements
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Clinical References Provides recommendations for further in-depth reading of a clinical nature
1. Ujhelyi MR, Robert S, Cummings DM, et al: Influence of digoxin immune Fab therapy and renal dysfunction on the disposition of total and free digoxin. Ann Intern Med 1993;119:273-277
2. Goodman and Gilman's: The Pharmacological Basis of Therapeutics. Tenth edition. New York. McGraw-Hill Book Company, 2001
3. Baselt RC. Disposition of Toxic Drugs and Chemicals in Man. Seventh edition. Foster City, CA. Biomedical Publications, 2004 pp 1254
4. Mozayani A: Ketamine-Effects on human performance and behavior. Forensic Sci Rev 2002;14:123-131