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 that are obtained 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
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, to monitor drug dependency, and to 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 medications)
Prescription medications, any type
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.
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: Saunders Elsevier; 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: Saunders Elsevier; 2009:chap 58.
Jacob L. Heller, MD, MHA, Emergency Medicine, Virginia Mason Medical Center, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.