Chapter 28 - Testing of Drugs of Abuse in Oral Fluid, Sweat, Hair, and Nail: Analytical, Interpretative, and Specimen Adulteration Issues

Abstract

Although approximately 90% drug testings are conducted using urine specimens, drug testing in alternative matrix such as oral fluid, sweat, hair, and nail are gaining importance as complementary approaches to traditional urine drug testings. Oral fluid testing like blood testing is very useful in detecting acute ingestion of drugs in a suspected drug-overdosed patient of an impaired driver. However, unlike a collection of blood specimens which requires venipuncture, oral fluid specimen can be collected on invasively. In addition, unlike urine specimen that can be easily adulterated, it is difficult to adulterate oral fluid specimen. Sweat patch can be used to monitor drug use over a period of several days to a week for an individual and is very useful in drug rehabilitation centers. Hair and nail specimen can provide a longer window of detection for drug use compared to oral fluid, urine, and sweat testing. Nail testing is useful in men who have short hair.