Toxicology Health Channel

Definition

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

Alternative Names

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

How the test is performed

Toxicology screening is most often done using a blood or urine sample. However, it may be done soon after swallowing the medication using stomach contents, which are obstained through gastric lavage or after vomiting.

For information on giving a blood sample from a vein see venipuncture.

For information providing a urine sample, see clean catch urine sample. In some circumstances, you may need to provide the urine sample in the presence of the nurse or technician to verify that the urine sample came from you and was not tampered with.

How to prepare for the test

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

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