Liquid chromatography-tandem mass spectrometry method for the bioanalysis of N,N-dimethyltryptamine (DMT) and its metabolites DMT-N-oxide and indole-3-acetic acid in human plasma.

A new LC-MS/MS method accurately measures the psychedelic compound DMT and its major metabolites IAA and DMT-NO in human plasma. The assay uses a simple protein precipitation step, a pentafluorophenyl column for separation, and detects analytes via mass spectrometry. Calibration ranges cover 0.25–250 ng/mL for DMT, 0.1–100 ng/mL for DMT-NO, and 25–25,000 ng/mL for IAA (using a labeled internal standard to account for endogenous IAA). Accuracy ranged from 93% to 113% with precision ≤11%. The method successfully determined pharmacokinetic parameters in participants receiving a 90-minute intravenous infusion of 1 mg/min DMT. It is easy to use, has a short run time, and is suitable for clinical DMT pharmacokinetic and metabolism studies.

Study at a glance

Abstract

The indole alkaloid N,N-dimethyltryptamine (DMT) induces psychedelic effects in humans. In addition to ceremonial and recreational use, DMT is subject to clinical investigations. Sensitive bioanalytical methods are required to assess the pharmacokinetics of DMT and its metabolites in human plasma. Here, a high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of DMT and its major metabolites indole-3-acetic acid (IAA) and DMT-N-oxide (DMT-NO) was developed and validated. As IAA is an endogenous component of human plasma, 13C6-IAA was used to determine IAA concentrations. After simple protein precipitation with methanol, analytes were separated on a pentafluorophenyl column. A gradient consisting of 0.1% (v/v) formic acid in a methanol-water mixture was applied for analyte separation. The analytes were detected by positive electrospray ionization followed by multiple reaction monitoring. The calibration range of the assay was 0.25-250 ng/mL for DMT, 0.1-100 ng/mL for DMT-NO, and 25-25,000 ng/mL for 13C6-IAA. The intra- and inter-assay accuracy was 93-113% for all analytes at all quality control levels, with coefficient of variation ≤ 11%. All analytes were stable under storage conditions relevant for the analysis of large batches of study samples. The validated method was capable of assessing pharmacokinetic (PK) parameters of DMT and its metabolites in study participants intravenously perfused with 1 mg/min DMT for 90 min. Overall, the developed method is easy-to-use, has a short run time, and qualifies for PK and metabolism studies of DMT in clinical settings.