Medical Experts
Johnson-Davis
McMillin
Emergency toxicology focuses on the diagnosis, management, and prevention of poisoning due to drugs, occupational and environmental toxins, and biological agents. Examples of exposures include acute drug overdoses, hazardous exposure to chemical products, and the management of drug withdrawal syndromes.
Quick Answers for Clinicians
In emergency situations, there are no specific timing recommendations; instead, specimens should be collected as soon as possible.
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 within an average window of detection of 1-3 days.
Test results should be interpreted based on 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). Note that adverse drug responses can occur even when drug concentrations are within the therapeutic range.
Toxicology test results are useful not only to determine patient exposure and assess symptoms of toxicity, but also for serial monitoring to evaluate treatment efficacy and determine if toxin concentrations have 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 acetaminophen poisoning), retest intervals are determined on a case-by-case basis.
Specimen Selection
Whole blood, serum, or plasma is preferred for most testing because these specimens can provide both quantitative and qualitative information. Urine may be used in select cases when only qualitative information is needed.
Frequently Asked Questions
What is the definition of half-life?
The half-life of a drug refers to the time required for 50% of the drug to be eliminated from blood.
What is the definition of steady-state concentration?
Steady-state concentration occurs when the rate of drug administration is equal to the rate of elimination. Generally, steady-state concentration can be achieved after an individual has consistently administered the drug for the duration of 5-7 half-lives (eg, if a drug has a half-life of 24 hours and is administered once a day, then steady-state concentration can be achieved after 5-7 days of drug administration).
What is the window of detection of drugs in blood, serum, plasma, and urine specimens?
In general, the window of detection in blood, serum, and plasma is 1-2 days after drug administration. Urine specimens typically have an average window of detection of 1-3 days.
The window of detection for drugs is dependent on several factors, including the following:
- Half-life of the drug
- Drug dose
- Frequency of drug administration
- Route of administration
- Drug formulation
- Chemistry of the drug (eg, solubility, stability)
- Patient age
- Patient body composition and sex
- Patient pathophysiology and pharmacokinetics
- Coadministration of other medications
- Hydration and nutrition status
- Analytical limitations of testing
Can gel separator tubes be used for toxicology testing?
Gel separator tubes are not recommended for testing in toxicology. Drugs that are lipid soluble may be absorbed into the gel, which may cause a falsely low result.
Further Resources
ARUP Laboratory Tests
Quantitative Gas Chromatography
Toxic level: >100 mg/dL
Quantitative Gas Chromatography
Toxic level:
- Isopropanol: >50 mg/dL
- Acetone, quantitative: >100 mg/dL
- Ethanol: >250 mg/dL
- Methanol: >20 mg/dL
Quantitative Gas Chromatography
Toxic level: >250 mg/dL
Qualitative Enzyme Immunoassay/Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Quantitative Enzymatic Assay
Toxic level: >20 mg/dL
Quantitative Gas Chromatography
Toxic level:
- Isopropanol: >50 mg/dL
- Acetone, quantitative: >100 mg/dL
Quantitative Gas Chromatography
Toxic level: >20 mg/dL
Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring topic for testing options.
Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring topic for testing options.
Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring topic for testing options.
Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Qualitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Qualitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Qualitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Qualitative Liquid Chromatography-Tandem Mass Spectrometry
For a complete list of drugs and drug metabolites detected, refer to the Drug Profile, Expanded Targeted Panels Test Fact Sheet
Qualitative Liquid Chromatography-Tandem Mass Spectrometry
For a complete list of drugs and drug metabolites detected, refer to the Drug Profile, Expanded Targeted Panels Test Fact Sheet
Qualitative Enzyme-Linked Immunosorbent Assay (ELISA)/Quantitative Gas Chromatography-Mass Spectrometry (GC-MS)/Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Qualitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Qualitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Gas Chromatography-Mass Spectrometry
Gas Chromatography-Mass Spectrometry (GC-MS)
Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Qualitative Enzyme-Linked Immunosorbent Assay/Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Quantitative Gas Chromatography-Mass Spectrometry
Note: Also refer to ARUP Consult’s Drug Testing topic for testing options.
Qualitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring and Drug Testing topics for more testing options.
Qualitative Enzyme Immunoassay/Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Qualitative Enzyme Immunoassay/Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Qualitative Enzyme Immunoassay/Quantitative Gas Chromatography-Mass Spectrometry
Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Qualitative Enzyme Immunoassay/Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Qualitative Enzyme Immunoassay/Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Qualitative Enzyme Immunoassay/Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Spectrophotometry
Note: Refer to ARUP Consult’s Therapeutic Drug Monitoring topic for testing options.
Note: Refer to ARUP Consult’s Nicotine Exposure and Metabolites topic for more testing options.
Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Quantitative High Performance Liquid Chromatography-Tandem Mass Spectrometry
Quantitative Liquid Chromatography-Tandem Mass Spectrometry
Note: Refer to ARUP Consult’s Trace Elements–Deficiency and Toxicity topic for testing options.
References
Goldfrank's Toxicologic Emergencies
Hoffman R, Howland M, Lewin N, et al. Goldfrank's Toxicologic Emergencies. 10th ed. McGraw-Hill Education/Medical; 2014.
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Wu AH, McKay C, Broussard LA, et al. National academy of clinical biochemistry laboratory medicine practice guidelines: recommendations for the use of laboratory tests to support poisoned patients who present to the emergency department. Clin Chem. 2003;49(3):357-379.
Note: Refer to ARUP Consult’s Alcohol Use Biomarkers topic for more testing options.