Locations Main Campus: Chesterfield, MO 63017   |   Locations
314-434-1500 314-434-1500   |   Contact Us

Multimedia Encyclopedia


 
E-mail Form
Email Results

 
 
Print-Friendly
Bookmarks
bookmarks-menu

Toxicology screen

Barbiturates - screen; Benzodiazepines - screen; Amphetamines - screen; Analgesics - screen; Antidepressants - screen; Narcotics - screen; Phenothiazines - screen; Drug abuse screen; Blood alcohol test

 

A toxicology screen refers to various tests that determine the type and approximate amount of legal and illegal drugs a person has taken.

How the Test is Performed

 

Toxicology screening is most often done using a blood or urine sample. However, it may be done soon after the person swallowed the medication, using stomach contents taken through gastric lavage (stomach pumping) or after vomiting.

 

How to Prepare for the Test

 

No special preparation is needed. If you are able, tell your health care provider what drugs (including over-the-counter medications) you have taken, including when you took them and how much you consumed.

This test is sometimes part of an investigation for drug use or abuse. Special consents, handling and labeling of specimens, or other procedures may be required.

 

How the Test will Feel

 

Blood test:

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Urine test:

A urine test involves normal urination. There is no discomfort.

 

Why the Test is Performed

 

This test is often done in emergency medical situations. It can be used to evaluate possible accidental or intentional overdose or poisoning. It may help determine the cause of acute drug toxicity, monitor drug dependency, and determine the presence of substances in the body for medical or legal purposes.

Additional reasons the test may be performed:

  • Alcoholism
  • Alcohol withdrawal state
  • Altered mental state
  • Analgesic nephropathy (kidney poisoning)
  • Complicated alcohol abstinence (delirium tremens)
  • Delirium
  • Dementia
  • Drug abuse monitoring
  • Fetal alcohol syndrome
  • Intentional overdose
  • Seizures
  • Stroke caused by cocaine use
  • Suspected sexual assault
  • Unconsciousness

If the test is used as a drug screen, it must be done within a certain amount of time after the drug was taken, or while forms of the drug can still be detected in the body. Examples are below:

  • Alcohol: 3 to 10 hours
  • Amphetamines: 24 to 48 hours
  • Barbiturates: up to 6 weeks
  • Benzodiazepines: up to 6 weeks with high level use
  • Cocaine: 2 to 4 days; up to 10 to 22 days with heavy use
  • Codeine: 1 to 2 days
  • Heroin: 1 to 2 days
  • Hydromorphone: 1 to 2 days
  • Methadone: 2 to 3 days
  • Morphine: 1 to 2 days
  • Phencyclidine (PCP): 1 to 8 days
  • Propoxyphene: 6 to 48 hours
  • Tetrahydrocannabinol (THC): 6 to 11 weeks with heavy use

 

Normal Results

 

Normal value ranges for over-the-counter or prescription medications may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

A negative value usually means that alcohol, prescription medications that have not been prescribed, and illegal drugs have not been detected.

A blood toxicology screen can determine the presence and level (amount) of a drug in your body.

Urine sample results are usually reported as positive (substance is found) or negative (no substance is found).

 

What Abnormal Results Mean

 

Elevated levels of alcohol or prescription drugs can be a sign of intentional or accidental intoxication or overdose.

The presence of illegal drugs or drugs not prescribed for the person indicates illicit drug use .

 

Risks

 

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

  • Excessive bleeding
  • Fainting or feeling light-headed
  • Hematoma (blood accumulating under the skin)
  • Infection (a slight risk any time the skin is broken)

 

Considerations

 

Substances that may be detected on a toxicology screen include:

  • Alcohol (ethanol) -- "drinking" alcohol
  • Amphetamines
  • Antidepressants
  • Barbiturates and hypnotics
  • Benzodiazepines
  • Cocaine
  • Flunitrazepam (Rohypnol)
  • Gamma hydroxybutyrate (GHB)
  • Marijuana
  • Narcotics
  • Non-narcotic pain medicines, including acetaminophen and anti-inflammatory drugs
  • Phencyclidine (PCP)
  • Phenothiazines (antipsychotic or tranquilizing medicines)
  • Prescription medicines, any type

 

 

References

McPherson RA, Pincus MR. Toxicology and therapeutic drug monitoring. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods . 21st ed. Philadelphia, PA: Elsevier Saunders; 2006:chap 23.

Sachs C, Wheeler M. Examination of the sexual assault victim. In: Roberts JR, Hedges JR, eds. Clinical Procedures in Emergency Medicine . 5th ed. Philadelphia, PA: Elsevier Saunders; 2009:chap 58.

Tintinalli JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM. Toxicology and pharmacology. In: Tintinalli JE, Kelen GD, Stapczynski JS, Ma OJ, Cline DM, eds. Emergency Medicine: A Comprehensive Study Guide . 6th ed. Columbus, OH: McGraw-Hill; 2006:section 14.

 
  • Blood test - illustration

    Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.

    Blood test

    illustration

    • Blood test - illustration

      Blood is drawn from a vein (venipuncture), usually from the inside of the elbow or the back of the hand. A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. Preparation may vary depending on the specific test.

      Blood test

      illustration

    Self Care

     

      Tests for Toxicology screen

       

       

      Review Date: 1/26/2015

      Reviewed By: Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

      The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

       
       
       

       

       

      A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.



      Content is best viewed in IE9 or above, Firefox and Google Chrome browser.