Abused and Designer Drugs and How They Escape Detection

Summary

In most healthcare facilities, toxicology laboratories have moved from a more general toxicology screen to a more limited screen. This limited screen will usually consist of a serum ethanol test by an enzymatic assay and a urine immunoassay screen for 5–10 drug classes based on commercially available immunoassay kits. These may be supplemented by serum tests for salicylate, acetaminophen, benzodiazepines and tricyclic antidepressants by immunoassay or spot tests. Although immunoassays are quite useful for rapid screening of many drugs, there are some limitations associated with this limited screening approach. This chapter discusses these limitations with regard to drug-facilitated sexual assault drugs, hallucinogenic amines, miscellaneous hallucinogens and opiates. One limitation is the fact that not all drug classes or drugs within a class are detected by these tests. In addition, some of the drugs discussed have very limited detection windows or exhibit instability that may limit or prevent their detection. The end result of a “not detected” result may be due not only to the absence of analyte but also to the specimen being collected too late for analyte detection, a lack of sensitivity of the employed analytical methodology or the degradation of the analyte during storage.