Mayo Test Catalog, (Sorted By Test Name) - Mayo Medical ...

METQU
60040
MET
81032
Interpretation: The minimal effective serum concentration for analgesia is 30 ng/mL. Peak
therapeutic serum concentrations of 30 to 90 ng/mL occur 4 hours after dose. Patients continuously
administered methadone develop tolerance and have higher serum concentrations than indicated by the
reference range; these patients may tolerate concentrations up to 400 ng/mL. Methadone concentrates in
serum; the ratio of blood to serum methadone is 0.75.
Reference Values:
Single dose: 30-90 ng/mL
Maintenance dose: 400-1,000 ng/mL
Clinical References: 1. Goodman LS, Gillman A, Hardman JG, et al: The pharmacological basis
of therapeutics. 9th edition. Edited by JG Hardman, LE Limbird. New York, McGraw-Hill Book
Company, 1996, pp 544-555 2. Baselt RC: Disposition of toxic drugs and chemicals in man. 5th edition.
Foster City, CA, Chemical Toxicology Institute, 2000, pp 523-527
Methaqualone, Urine
Clinical Information: Methaqualone is a sedative hypnotic drug that is not available in the United
States as a prescription drug. It has also been used illegally as a recreational drug, commonly known as
quaaludes (particularly in the 1970s in North America). The biologic half-life is 20 to 60 hours, and is
detectable in urine for 4 to 6 days after use.
Useful For: Detecting drug abuse involving methaqualone
Interpretation: The presence of methaqualone in urine at >100 ng/mL indicates use of this drug.
Reference Values:
Negative
Positives are reported with a quantitative GC-MS result.
Cutoff concentrations:
IMMUNOASSAY SCREEN