Temporal patterns of tramadol in hair after a single dose

• Published in: Forensic science international 2020-11, Vol.316, p.110546, Article 110546
• Main Authors: Johansen, Sys Stybe, Dang, Linda Tuong Vy Le, Nielsen, Marie Katrine Klose, Haage, Pernilla, Kugelberg, Fredrik Carl, Kronstrand, Robert
• Format: Article
• Language: English
• Subjects: Adult; Analgesics, Opioid - administration & dosage; Analgesics, Opioid - analysis; Analytical chemistry; Anesthesia; Chromatography, Liquid; CYP2D6; CYP2D6 protein; Cytochrome P450; Dosage; Drug dosages; Drug facilitated crime; Enzymes; Female; Forensic sciences; Hair; Hair - chemistry; Hair analysis; Healthy Volunteers; Humans; Ingestion; Male; Mass Spectrometry; Metabolites; Phenotypes; Pigmentation; Psychotropic drugs; Quality control; Sampling; Segmental hair analysis; Segments; Sex crimes; Single drug exposure; Time Factors; Tramadol; Tramadol - administration & dosage; Tramadol - analogs & derivatives; Tramadol - analysis; Young Adult
• ISSN: 0379-0738; 1872-6283; 1872-6283
• DOI: 10.1016/j.forsciint.2020.110546

[Display omitted] •Controlled study with data from 17 subjects administered a single dose of tramadol.•Tramadol present in hair to at least 4 months after single ingestion.•Narrow segmental analysis of hair enabled a good estimate of time of drug ingestion.•Tramadol metabolite findings may depend on subject CYP2D6 phenotype.•Significant wash out and sweat effects were observed. This controlled study aimed to measure concentrations of tramadol (TRA) and its two main metabolites, N-desmethyltramadol (NDMT) and O-desmethyltramadol (ODMT), in hair following a single dose ingestion and to investigate the distribution patterns in hair by segmental analysis of hair samples taken at several sampling time points after ingestion. An oral dose (50 or 100mg) of TRA was administered to 17 healthy volunteers. Hair samples were collected prior to drug administration and 14, 30, 60 and 120 days after ingestion. Each sample was segmented in 5mm segments and washed. The analytes were extracted from pulverized hair by incubation in extraction media for 18h at 37°C. A validated UHPLC–MS/MS method was used to quantify the analytes at a LLOQ of 0.001ng/mg. Hair segments corresponding to the time of ingestion were positive for TRA and the metabolites of each sampling time point, although neighboring segments also showed positive results. The highest concentrations for both dosage groups were observed in the proximal segment of hair collected 14 days after ingestion for all subjects: 0.061–0.95ng TRA/mg, 0.012–0.86ng NDMT/mg and 0.009–0.17ng ODMT/mg (n=16). Generally, the TRA concentration was higher than the metabolites concentrations but depended on the CYP2D6 phenotype. The metabolite to TRA ratios were stable within a subject over the sampling time points, however it varied greatly between subjects. No significant differences in hair concentrations were found between the two dosage groups at each sampling time. Several confounding factors were identified such as hair pigmentation and internal sweat. We showed that analysis of 5mm segments improved the determination of the exposure time after a single ingestion of TRA. In addition, in the later sampling time points the analytes were spread more between segments and the total drug amount of each later sampling time point declined up to a 100% (median: 75%) due to wash out. The presented results are important additions to the sparse literature reporting single dose of psychoactive drugs in hair.