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Barbiturate screening (urine)

Published: August 9, 2026Updated: August 17, 2026

This test checks for the presence of barbiturate drugs in your urine, often used to detect recent use of sedative medications.

Quick summary

["A barbiturate urine screen helps identify if certain medications were recently consumed, which may be important for medical or legal reasons."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
3375-3
Short code
Deprecated Barbiturate Scn Present Ur
Synonyms
Deprecated Barbiturate Scn Present Ur
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Ref low
3.5
Ref high
7.2
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms of barbiturate use, such as drowsiness, confusion, or unusual behavior. It could also be part of a routine screening in certain settings, like substance abuse evaluations or workplace safety checks.

What to Expect Before the Test

No special preparation is needed. You’ll provide a urine sample in a private area, similar to other routine urine tests. Avoid drinking excessive fluids before the test, as it may dilute the sample.

What the Test Results Mean

A positive result indicates the presence of barbiturates in your urine, which may suggest recent use. A negative result means no detectable levels were found. Results are qualitative (present or absent) and not used to determine the exact amount or duration of use.

Possible Causes of Positive Results

Barbiturates are prescription medications used to treat seizures or insomnia. If you’ve taken these drugs as directed by your doctor, a positive result may be expected shortly after use. False positives can sometimes occur due to contamination or cross-reacting substances, but this is rare.

Reference range

NCBI: Uric Acid Male 3.5-7.2 mg/dL; Female 2.5-6.8 mg/dLN/A

Specimen: urine

No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Barbiturate urine screen

Frequently asked questions

What does a positive result mean for my health?
A positive barbiturate screen may raise concerns if used without medical supervision, as misuse can lead to serious health risks, including overdose or dependence. Your healthcare provider will discuss next steps, such as further testing or counseling, depending on your situation.
Can I have false results from this test?
While rare, false positives can occur if the sample is contaminated or if other substances cross-react with the test. False negatives are less likely but can happen if the drug was used shortly before testing or if the concentration was very low. Always follow up with your provider if results are unclear.
How long do barbiturates stay in urine?
Barbiturates typically clear from urine within 2–5 days after the last dose, depending on the specific medication and individual metabolism. Some drugs may linger longer, so results may reflect recent use rather than long-term exposure.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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 17, 2026. · Read our editorial policy