Determination of trimeprazine-facilitated sedation in children by hair analysis

Abstract

Trimeprazine or alimemazine is largely used as an antipruritic agent, but it is also used for insomnia, cough, and oral premedication in pediatric day surgery. The first cases involving repetitive sedation linked to the use of trimeprazine as a drug-facilitated crime and subsequent impairment of two children are reported. Because of the long delay between the alleged crime and clinical examination, collection of blood or urine was of little value. This is the reason why the laboratory developed an original approach based on hair testing by liquid chromatography - tandem mass spectrometry. A strand of hair from each child was sampled about 2 months after the first suspicion of administration and was cut into small segments. After cutting into small pieces, 20 mg of hair was incubated overnight in a phosphate buffer (pH 8.4). The aqueous phase was extracted by 5 mL of a mixture of diethyl ether/methylene chloride (80:20) in presence of diazepam-d5 used as the internal standard (IS). Hair extract was separated on a XTerra MS C18 column using a gradient of acetonitrile and formate buffer. Detection was based on two daughter ions: transitions m/z 299.3 to 299.0 and 100.0 and m/z 289.9 to 154.0 for trimeprazine and the IS, respectively. In the hair of the two subjects, trimeprazine was detected at concentrations in the range 23 to 339 pg/mg. The stepmother, who was the perpetrator in both cases, did not challenge the use of trimeprazine as a sedative drug.