What this test measures
"Opiates" classically refers to the natural alkaloids of the opium poppy (morphine, codeine) and their close semi-synthetic relatives (heroin, hydrocodone). The standard immunoassay screen detects morphine and is positive after intake of morphine itself, codeine (which is metabolised to morphine), or heroin (metabolised to 6-monoacetylmorphine and then morphine). Synthetic opioids like methadone, fentanyl, tramadol, oxycodone, and buprenorphine are NOT reliably picked up by this assay and need separate-specific tests.
A positive screen should always be confirmed by LC-MS/MS, which can also detect 6-MAM — the heroin-specific metabolite that confirms heroin use as opposed to prescription codeine or poppy-seed ingestion.
Why it matters
Opioid use disorder is a growing concern in India — heroin in border states, pharmaceutical opioid misuse (codeine-containing cough syrups, tramadol) across the country, and now prescription opioid escalation in chronic pain. The opiates panel is used in three main settings.
Emergency: confirming an opioid cause of an unresponsive patient with pinpoint pupils and slow breathing — directs immediate naloxone treatment. Addiction medicine: monitoring abstinence in patients on buprenorphine or methadone substitution therapy. Workplace and forensic: pre-employment screening, post-accident testing, and medico-legal investigations. A positive opiate screen alone does not distinguish prescribed analgesia from illicit use — clinical history and LC-MS confirmation are essential.
How to prepare
No fasting required. Avoid poppy-seed foods (some bakery breads, certain Indian sweets and curries that use khus-khus) for at least 24–48 hours before the test, as they can produce true-positive morphine results without illicit use. Disclose all prescribed and over-the-counter medications including codeine-based cough syrups, prescription painkillers, and antidiarrhoeal medicines.
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 |
|---|---|---|---|
| Opiates (Morphine equivalent) (ng/mL)[1][2][3] | Not detected (typical screen cut-off 300 ng/mL urine, 10 ng/mL serum) | Not detected: rules out morphine, codeine, or heroin use within the previous 1–3 days (urine), or 12–24 hours (blood). | Positive: confirms exposure to a natural or semi-synthetic opioid. Could be prescribed (post-op analgesia, codeine cough syrup), illicit (heroin), or dietary (poppy seeds). Always confirm by LC-MS. Presence of 6-MAM is specific for heroin use within the previous 8 hours. |
Which opioids does an "opiate screen" detect?
| Drug | Detected by routine opiate screen? |
|---|---|
| Morphine | Yes |
| Codeine | Yes (metabolises to morphine) |
| Heroin | Yes (metabolites detected — 6-MAM is heroin-specific) |
| Hydrocodone / Hydromorphone | Variable — depends on assay |
| Oxycodone | Usually NOT — needs specific oxycodone assay |
| Methadone | No — needs specific methadone assay |
| Fentanyl | No — needs specific fentanyl assay |
| Tramadol | No — needs specific tramadol assay |
| Buprenorphine | No — needs specific buprenorphine assay |
Frequently asked questions
Can poppy seeds cause a positive opiate test?
Yes. Indian poppy seeds (khus-khus) can produce true-positive morphine results at typical screening cut-offs for 24–48 hours after eating. This is why higher cut-offs are sometimes used and why LC-MS confirmation with the heroin-specific 6-MAM metabolite is so important.
Does this test detect tramadol?
No. Tramadol is a synthetic opioid and is not detected by routine opiate immunoassays. A specific tramadol assay is needed.
How long are opiates detectable?
Blood: 12–24 hours. Urine: 1–3 days for occasional use, longer for heavy chronic use. Hair: up to 90 days. Saliva: 1–4 days.
What is 6-MAM and why does it matter?
6-monoacetylmorphine (6-MAM) is a unique metabolite produced when heroin breaks down. It is specific for heroin — not codeine, morphine, or poppy seeds — and is detectable for about 8 hours after use. A positive 6-MAM result is forensic-grade confirmation of heroin exposure.
What does the test mean if I am on prescription painkillers?
A positive opiate screen does not distinguish prescribed from illicit. Bring documentation of any prescribed opioid (morphine, codeine, tramadol, oxycodone) to the test. The LC-MS confirmation can then quantify the specific drug and your treating doctor can compare with the expected dose.
Why is this important in suspected overdose?
An unconscious patient with pinpoint pupils and slow breathing is given naloxone — a fast-acting opioid antidote. The opiate test confirms the working diagnosis and guides repeat dosing if needed. Note: naloxone reverses opiates but does NOT reverse benzodiazepines, alcohol, or other sedatives.
Is this test used for OST (opioid-substitution therapy) monitoring?
Indirectly — the test is used alongside methadone and buprenorphine-specific assays. A patient on methadone or buprenorphine should be negative on the standard opiate screen (no heroin/morphine), but positive on the specific OST drug assay. Combined panels help confirm adherence.
Related Drugs / Therapeutic Monitoring tests
Tests commonly ordered alongside OPIATES, or that help interpret an unexpected result.
Sources & references
- NCBI StatPearls — Opioid Toxicity · accessed 2026-05-30T00:00:00.000Z
- NIH NIDA — Opioids · accessed 2026-05-30T00:00:00.000Z
- CDC — Drug Overdose · accessed 2026-05-30T00:00:00.000Z
- Mayo Clinic Labs — Opiates Confirmation · accessed 2026-05-30T00:00:00.000Z
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