What this test measures
Urine immunoassay detects benzodiazepine-class compounds (diazepam, alprazolam, lorazepam, clonazepam, oxazepam, temazepam, midazolam and metabolites). Standard screen cutoff 200 ng/mL (some 100). Important limitation — newer / more potent benzodiazepines (alprazolam, clonazepam, lorazepam) may not be reliably detected by older assays designed for diazepam / oxazepam metabolites; check the assay specifications.
Why it matters
India has one of the world's highest per-capita benzodiazepine prescription rates outside of regulated psychiatric care, with widespread availability of alprazolam (Restil, Trika, Alprax) and diazepam without prescription. Screening contexts: workplace / pre-employment, forensic / medico-legal, deaddiction programme monitoring, suspected overdose, and rarely athletic testing (benzodiazepines are not WADA-banned). Cross-reactivity issues affect interpretation — assays designed for diazepam may miss alprazolam, clonazepam, lorazepam unless second-generation immunoassays are used.
How to prepare
Random urine sample. Disclose all prescription medications including diazepam (Calmpose), alprazolam (Restil, Alprax), clonazepam (Rivotril, Clonotril, Lonazep), lorazepam (Ativan), midazolam (Dormicum), and over-the-counter sleep aids.
Markers & reference ranges
Reference ranges below are typical adult values. Your lab's reported range may differ slightly based on the assay platform and patient demographics — always read your report against the range printed on it.
| Marker | Normal range | If low | If high |
|---|---|---|---|
| Urine Benzodiazepines (ng/mL)[1][2] | Negative (< 200 ng/mL screen cutoff) | Negative — no recent benzodiazepine use (or use of a benzodiazepine the assay doesn't detect well, e.g., alprazolam or clonazepam in some older assays). | Positive (≥ 200 ng/mL) — recent benzodiazepine use; confirm with GC-MS / LC-MS to identify the specific compound. Common sources: prescribed anxiolytic, sleep aid, alcohol-withdrawal treatment, recreational use, or rare false positives (sertraline, oxaprozin). |
Benzodiazepine detection windows
| Substance | Detection window (urine) | Notes |
|---|---|---|
| Short-acting (alprazolam, lorazepam, midazolam) | 1–3 days | May be missed by older immunoassays |
| Intermediate (oxazepam, temazepam) | 2–4 days | Diazepam metabolites |
| Long-acting (diazepam, clonazepam) | 5–14 days | Chronic use: up to 4–6 weeks |
Frequently asked questions
Will my anxiety medication test positive?
Yes — diazepam (Calmpose), alprazolam (Restil), clonazepam (Rivotril), lorazepam (Ativan) all produce positive urine benzodiazepine screens. Disclose your prescription so the result is interpreted as licit use.
Why might alprazolam test negative even though I take it?
Older immunoassays were calibrated to diazepam / oxazepam metabolites and may miss alprazolam, clonazepam, and lorazepam at standard doses. Confirmatory GC-MS / LC-MS detects them.
How long after my last dose will I still test positive?
Single low dose: 1–3 days. Chronic daily use: 5–14 days for short-acting, up to 4–6 weeks for long-acting (diazepam, clonazepam).
Is it dangerous to stop benzodiazepines suddenly?
Yes — sudden discontinuation after chronic use can cause severe withdrawal (seizures, agitation, autonomic instability). Always taper under medical supervision.
Can over-the-counter sleeping pills cause a positive?
Most OTC sleep aids (diphenhydramine, doxylamine) do NOT cross-react. Z-drugs (zolpidem, zopiclone, eszopiclone) are NOT benzodiazepines and typically do not produce positive benzodiazepine screens — they need separate assays.
Can sertraline cause a false positive?
Rarely — high-dose sertraline (an SSRI antidepressant) and the NSAID oxaprozin have been reported to cause false-positive benzodiazepine screens. Confirmation by GC-MS resolves the question.
Related Drugs / Therapeutic Monitoring tests
Tests commonly ordered alongside BENZODIAZEPINES, or that help interpret an unexpected result.
Sources & references
- SAMHSA — Urine Drug Testing Guidelines · accessed 2026-05-30T00:00:00.000Z
- NIH MedlinePlus — Drug Testing · accessed 2026-05-30T00:00:00.000Z
- StatPearls — Benzodiazepine Toxicity · accessed 2026-05-30T00:00:00.000Z
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