Home
HelpTest Code AMPHX Amphetamines Confirmation, Chain of Custody, Random, Urine
Useful For
Confirming drug exposure involving amphetamines such as amphetamine and methamphetamine, phentermine, pseudoephedrine/ephedrine, methylenedioxymethamphetamine, and methylenedioxyamphetamine.
Providing chain-of-custody for when 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 always under the control of personnel involved with testing the specimen; 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
Amphetamines Confirmation, CoC, USpecimen Type
UrineSpecimen Required
Supplies: Chain of Custody Kit (T282)
Container/Tube: Chain of custody kit containing the specimen containers, seals, and documentation required
Specimen Volume: 5 mL
Collection Instructions: Collect 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
1 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Urine | Refrigerated (preferred) | 28 days | |
| Ambient | 28 days | ||
| Frozen | 28 days |
Reject Due To
| Gross hemolysis | OK |
| Gross icterus | OK |
Clinical Information
Amphetamines are sympathomimetic amines that stimulate central nervous system activity and, in part, suppress the appetite. Phentermine, amphetamine, and methamphetamine are prescription drugs for weight loss. All other amphetamines are Class I (distribution prohibited) compounds. In addition to their medical use as anorectic drugs, they are used in the treatment of narcolepsy, attention-deficit disorder/attention-deficit hyperactivity disorder, and minimal brain dysfunction.
Because of their stimulant effects, the drugs are commonly sold illicitly and abused. Physiological symptoms associated with very high amounts of ingested amphetamine or methamphetamine include elevated blood pressure, dilated pupils, hyperthermia, convulsions, and acute amphetamine psychosis.
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.
Reference Values
Negative
Cutoff concentrations:
IMMUNOASSAY SCREEN: <500 ng/mL
Liquid chromatography tandem mass spectrometry:
Amphetamine: <25 ng/mL
Methamphetamine: <25 ng/mL
Phentermine: <25 ng/mL
Methylenedioxyamphetamine: <25 ng/mL
Methylenedioxymethamphetamine: <25 ng/mL
Pseudoephedrine/ephedrine: <25 ng/mL reported as negative
Interpretation
The presence of amphetamines in urine is a strong indicator that the patient has used these drugs within the past 3 days.
Methamphetamine has a half-life of 9 to 24 hours and is metabolized by hepatic demethylation to amphetamines. Consequently, a sample containing methamphetamine usually also contains amphetamine. Amphetamine has a half-life of 4 to 24 hours.
Amphetamine is not metabolized to methamphetamine; absence of methamphetamine in the presence of amphetamine indicates the primary drug of abuse is amphetamine. However, trace amounts of methamphetamine can be detected in amphetamine-based prescription drugs (eg, Adderall), but the concentrations are typically less than 1% of the amphetamine concentrations.
3,4-Methylenedioxymethamphetamine (Ecstasy, MDMA) is metabolized to 3,4-methylenedioxyamphetamine (MDA).
Methylenedioxyethylamphetamine is also metabolized to MDA.
The detection interval in urine for amphetamine type stimulants is typically to 3 to 5 days after last ingestion.
This test will produce true-positive results for urine specimens collected from patients who are administered Adderall and Benzedrine (contain amphetamine); Desoxyn and Vicks Inhaler (contain methamphetamine); Selegiline, and famprofazone (metabolized to methamphetamine and amphetamine); and clobenzorex, fenethylline, fenproporex, and mefenorex, which are amphetamine pro-drugs and metabolized to amphetamine.
Cautions
Over-the-counter sympathomimetics such as ephedrine and phenylpropanolamine are occasionally detected in the screening immunoassay.
Method Description
The amphetamine assay is based on the kinetic interaction of microparticles in a solution as measured by changes in light transmission. In the absence of sample drug, soluble drug conjugates bind to antibody-bound microparticles causing the formation of particle aggregates. As the aggregation reaction proceeds in the absence of sample drug, the absorbance increases. When a urine sample contains the drug in question, this drug competes with the drug derivative conjugate for microparticle-bound antibody. Antibody bound to sample drug is no longer available to promote particle aggregation, and subsequent particle lattice formation is inhibited. The presence of sample drug diminishes the increasing absorbance in proportion to the concentration of drug in the sample. Sample drug content is determined relative to the value obtained for a known cutoff concentration of drug.(Package insert: AMPS2. Roche Diagnostics; 06/2020)
The specimen is then diluted and then analyzed by liquid chromatography tandem mass spectrometry.(Unpublished Mayo method)
Day(s) Performed
Monday through Friday
Report Available
3 to 5 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
80325
80359
G0480 (if appropriate)
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| AMPHX | Amphetamines Confirmation, CoC, U | 97161-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| 6538 | Amphetamines Immunoassay Screen | 19261-7 |
| 36128 | Amphetamine-by LC-MS/MS | 20410-7 |
| 36129 | Phentermine-by LC-MS/MS | 20557-5 |
| 36130 | Methamphetamine-by LC-MS/MS | 16235-4 |
| 36131 | Pseudoephedrine/Ephedrine-by LC-MS/MS | 58707-1 |
| 36132 | MDA (Ecstasy metabolite)-by LC-MS/MS | 20545-0 |
| 36133 | MDMA (Ecstasy)-by LC-MS/MS | 18358-2 |
| 36134 | Amphetamines Interpretation | 69050-3 |
| 36135 | Chain of Custody | 77202-0 |
Method Name
Immunoassay/Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)