Journal Article

Experience with a Urine Opiate Screening and Confirmation Cutoff of 2000 ng/mL

Albert D Fraser and David Worth

in Journal of Analytical Toxicology

Volume 23, issue 6, pages 549-551
Published in print October 1999 | ISSN: 0146-4760
Published online October 1999 | e-ISSN: 1945-2403 | DOI:
Experience with a Urine Opiate Screening and Confirmation Cutoff of 2000 ng/mL

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Until recently, most laboratories used an opiate immunoassay screening and confirmation cutoff value of 300 ng/mL for codeine and morphine detection by gas chromatography-mass spectrometry (GC-MS). The cutoff value for opiates was increased to 2000 ng/mL or higher in various laboratories because of concerns that small doses of codeine and foods containing poppy seeds would give a positive opiate-screening result. Workplace drug-testing programs in the U.S. raised the opiate cutoff value to 2000 ng/mL on 30 November 1998. The objective of this study is to describe the results of opiate testing of 8600 urine specimens collected over 24 months with a 2000-ng/mL screening and confirmation (codeine and morphine) cutoff value. Specimens were screened by the EMIT®dau™ opiate assay using an in-house 2000-ng/mL morphine calibrator. Presumptive positive findings (N = 621) were analyzed quantitatively by GC-MS for codeine and morphine. One hundred and eighty six urine specimens were positive for codeine and morphine (> 2000 ng/mL), 298 specimens were positive for codeine only (> 2000 ng/mL) and 26 specimens were positive for morphine only (> 2000 ng/mL). All remaining specimens had codeine and morphine values < 2000 ng/mL. The codeine and morphine confirmation rate in this program reduced from 7.1% in 1994–1996 (300-ng/mL cutoff) to 2.1% in 1997–1998 with a 2000-ng/mL cutoff value. The codeine-only confirmation rate lowered from 6.6% (300-ng/mL cutoff) to 3.4% (2000-ng/mL cutoff). It was concluded that increasing opiate screening and codeine and morphine confirmation cutoff values led to > 300% reduction in the confirmed-positive rate for codeine and morphine and a 47% reduction in codeine-only confirmations in a urine drug-testing program where codeine was the major opiate used.

Journal Article.  0 words. 

Subjects: Medical Toxicology ; Toxicology (Non-medical)

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