Emergency Toxicology

Emergency toxicology focuses on the diagnosis, management, and prevention of poisonings due to drugs, occupational and environmental toxins, and biological agents. Examples of exposures include acute drug overdoses, hazardous exposures to chemical products, and the management of drug withdrawal syndromes.  

Quick Answers for Clinicians

When should specimens be collected for emergency toxicology testing?

In emergency situations, there are no specific timing recommendations; instead, specimens should be collected as soon as possible.

Which specimen is appropriate for emergency toxicology testing?

Whole blood, serum, or plasma specimens are typically preferred for most testing; quantitative results can be used to assess signs and symptoms of toxicity. Urine can be used to assess acute or chronic exposure.

How should toxicology test results be interpreted?

Test results should be interpreted relative to the established therapeutic or toxic range (if applicable), timing of specimen collection relative to the time of exposure, specimen type, and the patient’s clinical signs and symptoms of toxicity. Concomitant medications and factors relevant to the window of detection will also affect the interpretation of results (see Frequently Asked Questions). Whole blood, serum, and plasma specimens can be used to assess symptoms of toxicity. Adverse drug responses can occur even when the drug concentrations are within the therapeutic range. Urine specimens can be used to assess patient exposure within an average window of detection of 1-3 days. Testing can be used for serial monitoring to determine if treatment was effective and if the concentration of the toxin has decreased over time.

Indications for Testing

Testing for toxicity may be indicated in the following situations:

  • Accidental or intentional poisoning from illicit or licit substances
  • Decontamination or detoxification
  • Suspected overdose of licit or illicit substances in a patient presenting with altered cognition
  • Metabolic acidosis of unknown cause
  • Signs and symptoms of toxicity in the event of a known or suspected hazardous exposure

Timing of Specimen Collection

In an acute emergency, specimens should be collected as soon as possible if toxicity is suspected. If assessing decontamination or detoxification (eg, in the case of Tylenol poisoning), retest intervals are determined on a case-by-case basis.

Specimen Selection

Whole blood, serum, or plasma is used for most testing and can provide both quantitative and qualitative information. Urine may be used in select cases when only qualitative information is needed.

Frequently Asked Questions

ARUP Lab Tests

Alcohol Tests

Note: Refer to ARUP Consult’s Alcohol Use Biomarkers and Metabolic Acidosis topics for more testing options.

Monitor exposure to acetone

Toxic level: >100 mg/dL

Use to identify ethanol, methanol, isopropanol, or acetone ingestion

Toxic level:

  • Isopropanol: >50 mg/dL
  • Acetone, quantitative: >100 mg/dL
  • Ethanol: >250 mg/dL
  • Methanol: >20 mg/dL

Serum test to identify acute alcohol ingestion

Toxic level: >250 mg/dL

Useful for general screening in the assessment of ethanol exposure in the context of compliance and/or abuse

Aid in assessment of the etiology of anion gap acidosis

Determine whether ethylene glycol poisoning exists

Toxic level: >20 mg/dL

Monitor exposure to isopropanol

Toxic level:

  • Isopropanol: >50 mg/dL
  • Acetone, quantitative: >100 mg/dL

Monitor exposure to methanol

Toxic level: >20 mg/dL

Anticonvulsant/Antiepileptic Tests

Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring topic for testing options.

Antidepressant Tests

Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring topic for testing options.

Antipsychotic Tests

Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring topic for testing options.

Cannabinoid Tests

Detect exposure to cannabinoids

May be useful in the assessment of exposure to synthetic cannabinoids up to several days after exposure

Drug Detection Tests

May be useful in the assessment of acute exposure to bath salts

For assessment several days after exposure, refer to Bath Salts Panel, Urine (2008650)

May be useful in the assessment of exposure to bath salts up to several days after exposure

For assessment of acute exposure, Bath Salts Panel, Serum or Plasma (2011411) may be useful

Detect overdose exposure

Useful when identity or class of the drug or drugs of interest is not known

Not recommended for assessment in routine compliance and/or abuse contexts

Monitor patient compliance

Drug-Facilitated Sexual Assault Tests

Detect exposure

Useful for general screening to assess drug abuse

Positive drug screen results are confirmed

Monitor patient adherence and exposure

Illicit Drug Tests

Detect exposure

Useful for general screening to assess drug abuse

Positive drug screen results are confirmed

Monitor patient adherence

Nonopioid Pain Medication Tests

Note: Also refer to ARUP Consult’s Drug Testing topic for testing options.

Aid in the assessment of acetaminophen toxicity

Critical toxic values:

  • Post 4-hr ingestion: >150 µg/mL
  • Post 12-hr ingestion: >40 µg/mL

Optimize drug therapy and monitor patient adherence

Aid in assessment of the etiology of anion gap acidosis

Refer to ARUP Consult topic Metabolic Acidosis for more information

Toxic level: ≥31 mg/dL or greater

Opiate/Opioid Analgesic Tests

Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring and Drug Testing topics for more testing options.

Useful for general screening in context of compliance and/or abuse

For follow-up testing of a presumptive result, Buprenorphine and Metabolites, Urine, Quantitative (2010092) is preferred

Useful for general screening in context of compliance and/or abuse

For follow-up testing of a presumptive result, Fentanyl and Metabolite, Urine Quantitative (0092570) is preferred

Useful for general screening in context of compliance and/or abuse

For follow-up testing of a presumptive result, Meperidine and Metabolite, Urine, Quantitative (3000248) is preferred

Preferred test to follow up presumptive results

For general screening, Opiates, Urine Screen with Reflex to Quantitation (2005093) is preferred

Monitor patient adherence

For follow-up testing of a presumptive result, Opiates, Urine, Quantitative (0090364)

Useful for general screening in context of compliance and/or abuse

For follow-up testing of a presumptive result, Tapentadol and Metabolite, Urine, Quantitative (2003128) is preferred

Useful for general screening in context of compliance and/or abuse

For follow-up testing of a presumptive result, Tramadol and Metabolites, Urine, Quantitative (2002736) is preferred

Other Toxicant Tests

Monitor cyanide exposure

Toxic level: >100 µg/dL

Use to diagnose increased carbon monoxide levels and its poisoning

Sedative-Hypnotics Tests

Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring topic for testing options.

Stimulant Tests

Note: Refer to ARUP Consult’s Nicotine Exposure and Metabolites topic for more testing options.

Detect exposure

Monitor patient adherence

Use to detect and monitor nicotine, cotinine, and trans-3’-hydroxycotinine in serum or plasma

Serum or plasma testing may be useful when a valid urine specimen cannot be obtained (anuretic or dialysis)

Trace and Toxic Element Tests

Note: Refer to ARUP Consult’s Trace Elements–Deficiency and Toxicity topic for testing options. 

Medical Experts

Contributor
Contributor

McMillin

Gwendolyn A. McMillin, PhD
Professor of Clinical Pathology, University of Utah
Scientific Director, Mass Spectrometry Platform; Medical Director, Clinical Toxicology and Pharmacogenomics, ARUP Laboratories

References

Additional Resources
  • Medical Toxicology

    Dart RC, ed.. Medical Toxicology, 3rd. Philadelphia, PA: Lippincott Williams & Wilkins, 2003.

    Book
  • Goldfrank's Toxicologic Emergencies

    Hoffman R, Howland M, Lewin N, Nelson L, Goldfrank L. Goldfrank's Toxicologic Emergencies, 10th. New York, NY: McGraw-Hill Education/Medical, 2014.

    Book
  • Resources from the ARUP Institute for Clinical and Experimental Pathology®