Assault under the influence of methylphenidate documented by hair analysis

Abstract

Attention-deficit hyperactivity disorder (ADHD) is the most common neuro-behavioral disorder of childhood affecting school-aged children, with a prevalence generally estimated to be 5–10% of general population [1]. Methylphenidate (MPH), a phenethylamine derivative, is the available medication the most extensively studied and widely prescribed. MPH is reported to be absorbed quickly and completely from the gut after oral administration and it is rapidly hydrolyzed in the methyl ester linkage to its metabolite, ritalinic acid [2]. Although the drug is generally well tolerated, side effects of MPH may cause agitation, delirium or hallucinations. Given the drug is a stimulant, it is acceptable to consider that impairment can occur in case of ingestion [3]. This compound is listed as a drug of abuse in France and has no indication for adults, according to the European Pharmacopoeia. Hair sampling is a useful complement to blood and urine analyses to increase the window of detection and to permit differentiation of a single exposure from chronic use of a drug by segmentation. Moreover, due to the long delays that are frequently encountered between the event and the matter being reported to the police, hair can often be the only matrix capable of providing corroborative evidence of a committed event. The literature is very poor in papers dealing with the detection of MPH in hair. Marchei et al. [2] and Sticht et al. [4] have published procedures using liquid chromatography and gas chromatography coupled to mass spectrometry, respectively.