TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: BARBX    
Barbiturates Confirmation, Chain of Custody, Random, Urine

Useful For Suggests clinical disorders or settings where the test may be helpful

Detecting drug abuse involving barbiturates such as amobarbital, butalbital, pentobarbital, phenobarbital, and secobarbital

 

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.

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Adulterants testing will be performed on all chain of custody urine samples as per regulatory requirements.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Barbiturates represent a class of drugs that were originally introduced as sleep inducers. Butalbital is also used to control severe headaches. Mephobarbital and phenobarbital are frequently used to control major motor (grand mal) seizures. These drugs are commonly abused as "downers" to induce sleep after an amphetamine- or cocaine-induced "high."

 

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.

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.

Negative

Cutoff concentrations:

 

IMMUNOASSAY SCREEN

<200 ng/mL

 

BUTALBITAL BY GC-MS

<100 ng/mL

 

AMOBARBITAL BY GC-MS

<100 ng/mL

 

PENTOBARBITAL BY GC-MS

<100 ng/mL

 

SECOBARBITAL BY GC-MS

<100 ng/mL

 

PHENOBARBITAL BY GC-MS

<100 ng/mL

Interpretation Provides information to assist in interpretation of the test results

The presence of a barbiturate in urine indicates use of one of these drugs.

 

Most of the barbiturates are fast acting; their presence indicates use within the past 3 days.

 

Phenobarbital, commonly used to control epilepsy, has a very long half-life. The presence of phenobarbital in urine indicates that the patient has used the drug sometime within the past 30 days.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

No significant cautionary statements.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Baselt RC, Cravey RH: Disposition of Toxic Drugs and Chemicals in Man. Third edition. Year Book Medical Publishers, 1989

2. Langman LJ et al: Clinical Toxicology. In Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. Edited by N Rifai, AR Horvath, CT Wittwer. Sixth edition. Elsevier, 2018, pp 832-887