Interpretation of pharmaceutical drug concentrations in young children's head hair.

Three separate cases of child administration of prescription drugs are described. Following liquid-liquid extraction, high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was used to identify and quantify methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenyl-1-pyrrolidine (EDDP), tramadol, amitriptyline, and nortriptyline in children's hair. The children's age ranged from 14 months to 7 years; in all three cases, the drug in question was detected in more than one section of hair. Methadone was detected in the concentration range of 0.65-0.99 and 0.04-0.4 ng/mg; tramadol was detected in the concentration range of 1.5-2.2 ng/mg; amitriptyline and nortriptyline were detected in the concentration range of 0.18-1.06 and 0.38-2.0 ng/mg, respectively. In each case, the children's parents admitted to or were found guilty of drug administration to the child. These cases demonstrate the added value of hair testing and emphasize the importance of using hair samples to complement conventional analyses.