Use of an algorithm applied to urine drug screening to assess adherence to an OxyContin® regimen

Joseph E. Couto, PharmD, MBA; Lynn Webster, MD, FACPM, FASAM; Martha C. Romney, MS, JD, MPH; Harry L. Leider, MD, MBA; Ariel Linden, DrPH, MS

doi:10.5055/jom.2009.0035

Authors

Joseph E. Couto, PharmD, MBA
Lynn Webster, MD, FACPM, FASAM
Martha C. Romney, MS, JD, MPH
Harry L. Leider, MD, MBA
Ariel Linden, DrPH, MS

DOI:

https://doi.org/10.5055/jom.2009.0035

Keywords:

urine drug testing, medication adherence, OxyContin®, oxycodone, algorithm

Abstract

Objective: This study examined the ability of an algorithm applied to urine drug levels of oxycodone in healthy adult volunteers to differentiate among low, medium, and high doses of OxyContin®.
Participants and interventions: Thirty-six healthy volunteers were randomized to receive 80, 160, or 240 mg of daily OxyContin® to steady state while under a naltrexone blockade. During days 3 and 4 of the study, urine samples of all participants were collected, and oxycodone levels detected in the urine were obtained using a liquid chromatography-mass spectrometry (LC-MS-MS) assay.
Outcome measures: The concordance was calculated for raw and adjusted LC-MS-MS urine oxycodone values within each study participant between their third and fourth day values. Also, an analysis of medians was calculated for each of the dosage groupings using Bonett-Price confidence intervals for both raw and adjusted LC-MS-MS values.
Results: The concordance correlation coefficient for the raw LC-MS-MS values between days 3 and 4 was 0.689 (95% confidence intervals = 0.515, 0.864), whereas the concordance correlation coefficient for the LC-MS-MS values using the algorithm (ie, normalized values) was 0.882 (95% confidence intervals = 0.808, 0.956). Because of greater variability in the raw values, some overlap was observed in the confidence intervals of the various OxyContin® doses, whereas no overlap was observed in the normalized confidence intervals regardless of the application of a Bonferroni adjustment.
Conclusions: In contrast to raw LC-MS-MS values, an algorithm that normalizes oxycodone urine drug levels for pH, specific gravity, and lean body mass discriminates well among all three of the daily doses of OxyContin® tested (80, 160, and 240 mg), even with correcting for multiple analyses.

Author Biographies

Joseph E. Couto, PharmD, MBA

Pharmacoeconomics and Outcomes Research Fellow, Jefferson School of Population Health, Thomas Jefferson University, Philadelphia, Pennsylvania.

Lynn Webster, MD, FACPM, FASAM

Medical Director, Lifetree Clinical Research and Lifetree Pain Clinical, A Subsidiary of Lifetree Medical, Inc., Salt Lake City, Utah.

Martha C. Romney, MS, JD, MPH

Project Director, Jefferson School of Population Health, Thomas Jefferson University, Philadelphia, Pennsylvania.

Harry L. Leider, MD, MBA

Chief Medical Officer/SVP, Ameritox, Ltd., Baltimore, Maryland.

Ariel Linden, DrPH, MS

President, Linden Consulting Group, Hillsboro, Oregon.

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