Skip to content

Barbituratescnabsentur

Published: August 9, 2026Updated: August 16, 2026

A urine test to detect the presence of barbiturates, a class of sedative medications.

Quick summary

{"A 'absent' result means no barbiturates were detected in your urine","This is a normal/negative result indicating no recent barbiturate use","The test is commonly used for drug screening in clinical and workplace settings","Barbiturates are prescription sedatives used for anxiety, sleep, and seizure disorders"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
3372-0
Short code
BARSCR
Synonyms
Barbiturate Scn Absent Ur
Category
chemistry
Sample
urine
Container
Sterile, leak-proof urine collection container without preservative
Units
N/A
Ref low
200
Ref high
300
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
Immunoassay screening (e.g., EMIT, FPIA, KIMS, CEDIA) with confirmatory GC-MS or LC-MS/MS
CPT
80307
SNOMED
27220004
Specimen volume
20-50 mL of random urine (minimum 10 mL)
Stability
Refrigerated (2-8°C): 7 days; Frozen (-20°C): 30 days; Room temperature: 48 hours
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

A barbiturate urine screen is a laboratory test that analyzes a urine sample to detect the presence of barbiturates, which are a class of central nervous system depressant medications. Barbiturates are prescription drugs historically used as sedatives, hypnotics (sleep aids), and anticonvulsants. Examples include phenobarbital, pentobarbital, and secobarbital. This test looks for traces of these substances or their metabolites (breakdown products) in your urine.

Why is this test performed?

Healthcare providers may order this test for several reasons: (1) Routine drug screening for employment, pre-surgical clearance, or legal/forensic purposes; (2) Monitoring patients on long-term barbiturate therapy to ensure compliance; (3) Evaluating patients with symptoms of barbiturate overdose or toxicity; (4) Investigating unexplained symptoms such as excessive drowsiness, confusion, or respiratory depression.

What does 'absent' mean?

An 'absent' result means that no barbiturates were detected in your urine sample at the time of testing. This is considered a normal or negative result. It indicates that you have not taken barbiturate medications within the detection window, which is typically 1-6 weeks depending on the specific barbiturate and individual factors such as metabolism, kidney function, and hydration status.

Reference range

Negative (Absent). A positive (present) result typically indicates barbiturate concentration above the assay cutoff threshold of 200-300 ng/mL.N/A

Specimen: urine

No fasting required. Patients should be advised to provide accurate medication history. Collect urine under chain-of-custody if forensic or workplace testing is required.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

What does an 'absent' result mean for me?
An 'absent' result means that no barbiturates were found in your urine. This is a normal result if you have not been taking barbiturate medications. If you are prescribed barbiturates, this result may indicate that the medication has been fully eliminated from your body or that you have not taken your medication as directed.
How long do barbiturates stay in urine?
The detection window varies depending on the specific barbiturate, dose, frequency of use, and individual factors. Short-acting barbiturates may be detectable for 2-4 days, while long-acting barbiturates like phenobarbital can be detected for 2-3 weeks or longer after the last dose. Chronic use can extend the detection window.
What are barbiturates used for?
Barbiturates are sedative-hypnotic medications historically prescribed for anxiety, insomnia, and seizure disorders. Due to their potential for dependence and overdose, they have largely been replaced by safer alternatives like benzodiazepines. They are still occasionally used for seizure control (e.g., phenobarbital) and in some surgical settings.
Will a positive result show which specific barbiturate I took?
Standard urine screening tests detect the presence of barbiturates as a class but may not identify the specific drug. If a positive result requires confirmation or identification of the specific substance, a more sophisticated test called gas chromatography-mass spectrometry (GC-MS) may be performed.
Can this test be wrong?
While urine drug screens are generally reliable, false positives or negatives can occur. Certain medications, foods, or supplements may interfere with the test. False negatives can occur if the test is performed outside the detection window or if the urine is excessively diluted. Always discuss your results with your healthcare provider.
  1. 1
    Mayo Clinic - Drug TestingSource
  2. 2
    MedlinePlus - Barbiturate ScreenSource
  3. 3
    LabCorp - Barbiturates, UrineSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy