Detection Times of Carboxylic Acid Metabolites of the Synthetic Cannabinoids JWH-018 and JWH-073 in Human Urine.

Over the past years, use of synthetic cannabinoids has become increasingly popular. To draw the right conclusions regarding new intake of these substances in situations of repeated urinary drug testing, knowledge of their elimination rate in urine is essential. We report data from consecutive urine specimens from five subjects after ingestion of synthetic cannabinoids. Urinary concentrations of the carboxylic acid metabolites JWH-018-COOH and JWH-073-COOH were measured by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) with a limit of quantification of 0.1 ng/mL. In these subjects, specimens remained positive over a period of 20-43 (mean 27) days for JWH-018-COOH and over a period of 11-25 (mean 19) days for JWH-073-COOH. Detection times were shorter for subjects that appeared to have ingested only one, or a few, doses prior to urine collection in the study. Creatinine-normalized concentrations (CN-concentrations) slowly declined throughout the follow-up period in all subjects, suggesting that no new intake had taken place during this period. Mean elimination half-lives in urine were 14.0 (range 4.4-23.8) days for CN-JWH-018-COOH and 9.3 (range 3.6-16.8) days for CN-JWH-073-COOH. These data show that urine specimens could be positive for JWH-018-COOH for more than 6 weeks and JWH-073-COOH for more than 3 weeks after ingestion. However, such long detection periods require a low limit of quantification.