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
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.
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.
Non-narcotic pain medicines, including acetaminophen and anti-inflammatory drugs
Phenothiazines (antipsychotic or tranquilizing medicines)
Prescription medicines, any type
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.
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.