Opioid quantification via microsampling techniques to assess opioid use in human laboratory studies

Area of Science:

• Clinical Chemistry
• Forensic Toxicology
• Pharmacology

Background:

• Limited sample availability and cross-reactivity in urine screening challenge neurobiological studies.
• Serum offers better accuracy but requires larger blood volumes, posing collection challenges.
• Microsamples (<50 µL) provide a viable strategy for quantitative data in human studies.

Purpose of the Study:

• To develop and validate an automated serum-based LC-MS/MS assay for opioid quantification.
• To assess the assay's performance using minimal patient sample volumes (20 µL).
• To apply the assay in a clinical trial for patients with opioid use disorder.

Main Methods:

• Development and validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay.
• Automation of the assay for high-throughput analysis.
• Application in a clinical trial involving 20 patients receiving opioid agonist therapy and intranasal oxytocin or placebo.

Main Results:

• Accurate quantification of six opioids using only 20 µL of serum.
• Detection of opioids missed by standard urine strip tests during the treatment phase.
• Demonstration of a high-throughput, automated method superior to existing literature approaches.

Conclusions:

• The developed automated LC-MS/MS assay enables precise opioid quantification from minimal serum volumes.
• This microsample approach enhances efficiency and accuracy in clinical and research settings.
• The method improves the ability to monitor opioid use in vulnerable patient populations.