Laboratory Investigation of Drug Exposure

Valid specimens, specific toxicological analysis and insightful interpretation are the keys to proving the presence of a harmful drug. Urine, blood, hair and meconium specimens have different utility, depending on the clinical presentation, the time from exposure and the drug itself. Patient identification, consent, collection, labelling, documentation and secure transfer of specimens have to meet the evidential standards of the jurisdiction, if results are to have validity beyond their immediate clinical value. Clinical and forensic laboratories need to employ methods capable of unambiguously identifying the drug or metabolite. Correct interpretation requires insight into the clinical presentation and expert knowledge of the utility and limitations of each combination of specimen, analyte and methodology.