Benzodiazbldql
This test checks whether benzodiazepine medications are present in your blood.
{"Detects benzodiazepine drugs (e.g., Valium, Xanax, Ativan) in blood","Used to monitor medication use or diagnose overdose","Sample is collected as whole blood","Results may be affected by when you last took the medication","Commonly prescribed for anxiety, insomnia, and seizure disorders"}
Key facts at a glance
- LOINC
- 42662-7
- Short code
- BENZO
- Synonyms
- Benzodiaz Bld Ql
- Category
- chemistry
- Sample
- whole-blood
- Container
- Gray-top sodium fluoride/potassium oxalate tube (preferred for forensic and toxicology specimens); alternatively, red-top or lavender-top (EDTA) tube acceptable for clinical screening.
- Units
- N/A
- Ref low
- 100
- Ref high
- 200
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- Immunoassay (screening); confirmation by Gas Chromatography-Mass Spectrometry (GC-MS) or Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 80307
- SNOMED
- 33351009
- Specimen volume
- 5-10 mL whole blood
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Sodium fluoride preservative extends stability for forensic specimens.
- Hemolysis max
- 100
- Lipemia max
- 100
- Icterus max
- 50
- TAT
- 4–72 hours
- Order
- routine
What is this test?
The Benzodiazepines Blood Test is a toxicology test that detects whether benzodiazepine medications are present in your blood sample. Benzodiazepines are a class of prescription drugs commonly used to treat anxiety, insomnia, seizures, and muscle spasms. Examples include diazepam (Valium), lorazepam (Ativan), alprazolam (Xanax), and clonazepam (Klonopin).
Why is this test done?
This test may be ordered for several reasons: to monitor if a patient is taking their prescribed medication as directed, to check for drug misuse or unauthorized use, to diagnose suspected overdose or poisoning, or to evaluate patients with unexplained symptoms like excessive drowsiness or confusion. It may also be used in emergency situations or before certain medical procedures.
How is the test performed?
A healthcare provider will draw a blood sample from a vein in your arm using a needle. The sample is then sent to a laboratory for analysis. The test looks for the presence (qualitative) of benzodiazepines in your blood. No special preparation is typically needed, but you should inform your doctor about all medications you are taking.
What do the results mean?
A positive result means benzodiazepines were detected in your blood. A negative result means no benzodiazepines were detected, or the level is below the test's detection threshold. Your doctor will interpret the results based on your medical history, symptoms, and the specific medications you are known to be taking.
Reference range
Negative (cutoff varies by laboratory; commonly 100-200 ng/mL for total benzodiazepines as screening threshold). Therapeutic and toxic concentrations vary by specific benzodiazepine compound.N/A
No fasting required. Inform the ordering physician of all prescription medications, over-the-counter drugs, herbal supplements, and recreational substances prior to collection. Collect specimen prior to next scheduled dose when monitoring therapy.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
Do I need to fast before this test?
How long do benzodiazepines stay in blood?
Will this test show how much medication I took?
Can the test detect multiple benzodiazepines?
Sources
- 1
- 2
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.
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 15, 2026. · Read our editorial policy