Performance characteristics of the Cozart® RapiScan Oral Fluid Drug Testing System for opiates in comparison to ELISA and GC/MS following controlled codeine administration

• Published in: Forensic science international Vol. 141; no. 1; pp. 41 - 48
• Main Authors: Kacinko, Sherri L., Barnes, Allan J., Kim, Insook, Moolchan, Eric T., Wilson, Lisa, Cooper, Gail A., Reid, Claire, Baldwin, Dene, Hand, Chris W., Huestis, Marilyn A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 20.04.2004; Elsevier; The Lancet Publishing Group, a division of Elsevier Science Ltd; Elsevier Limited
• Subjects: Analgesics, Opioid - administration & dosage; Analgesics, Opioid - analysis; Analysis; Bias; Biological and medical sciences; Codeine; Codeine - administration & dosage; Codeine - analogs & derivatives; Codeine - analysis; Drug addictions; Drug dosages; Drug testing; Efficiency; Enzyme-Linked Immunosorbent Assay; False Negative Reactions; False Positive Reactions; Fluids; Forensic Medicine - methods; Forensic sciences; Gas chromatography; Gas Chromatography-Mass Spectrometry; Humans; Investigative techniques, diagnostic techniques (general aspects); Laboratories; Mass spectrometry; Medical sciences; Narcotics; Nightclubs; On-site tests; Onsite; Opiates; Oral fluid; Quality control; Saliva - chemistry; SAMHSA; Sensitivity and Specificity; Substance Abuse Detection - methods; Toxicology; Urinalysis; Opiates; Oral fluid; SAMHSA; On-site tests; Performance evaluation; Legal medicine; Characteristic; Oral administration; Antitussive agent; Enzyme immunoassay; Narcotic analgesic; Medical screening; Gas chromatography; Toxicological exploration; Characteristics; Test; Drug of abuse; Drug test; Performance; Mass spectrometry; ELISA assay; Comparative study
• ISSN: 0379-0738; 1872-6283
• DOI: 10.1016/j.forsciint.2003.12.003

Oral fluid is an interesting alternative matrix for drug testing in many environments, including law enforcement, workplace drug testing, and drug treatment facilities. Performance characteristics of the FDA-cleared, qualitative, Cozart® RapiScan Opiate Oral Fluid Drug Testing System (Opiate Cozart® RapiScan System or Opiate CRS) were compared to the semi-quantitative Cozart® Microplate EIA Opiate Oral Fluid Kit (Opiate ELISA) and to gas chromatography/mass spectrometry (GC/MS). The following oral fluid opiate cutoffs were evaluated: the GC/MS limit of quantification (LOQ) of 2.5mg/l; 15μg/l currently used for oral fluid testing in the United Kingdom (UK); 30μg/l (Opiate CRS cutoff); and 40μg/l, the proposed Substance Abuse and Mental Health Services Administration (SAMHSA) cutoff. Subjects provided informed consent to participate in this IRB-approved research and resided on the closed research ward throughout the study. Three oral codeine doses of 60mg/70kg were administered over a 7-day period. After a 3-week break, subjects received three doses of 120mg/70kg within 7 days. Oral fluid specimens (N=1273) were analyzed for codeine (COD), norcodeine (NCOD), morphine (MOR) and normorphine (NMOR) by GC/MS with an LOQ of 2.5μg/l for all analytes. MOR and NMOR were not detected in any sample; 26.5% of the specimens were positive for COD and 13.7% for NCOD. Opiate CRS uses a preset, qualitative cutoff of 10μg/l; this is equivalent to 30μg/l in undiluted oral fluid as the oral fluid collection process involves a 1:3 dilution with buffer. Sensitivity, specificity, and efficiency of Opiate CRS compared to Opiate ELISA were 98.6, 98.1, and 98.2% at a 30μg/l cutoff and 99.0, 96.2, and 96.6% at a 40μg/l cutoff. Compared to the much lower GC/MS LOQ of 2.5μg/l, sensitivity, specificity and efficiency were 66.8, 99.3 and 90.7%. Increasing the GC/MS cutoff to the current UK level yielded performance characteristics of 81.5% (sensitivity), 99.3% (specificity), and 95.4% (efficiency). Using a GC/MS cutoff identical to the preset Opiate CRS cutoff yielded sensitivity, specificity, and efficiency of 88.5, 99.2, and 97.5%, respectively. At the proposed SAMSHA confirmation cutoff of 40μg/l, sensitivity increased with little change in specificity and efficiency (91.3% sensitivity, 98.9% specificity, and 97.5% efficiency). Oral fluid is a suitable matrix for detecting drugs of abuse. Opiate CRS, with a 30μg/l cutoff, is sufficiently sensitive, specific and efficient for oral fluid opiate analysis, performing similarly to Opiate ELISA at the same cutoff, and having performance characteristics >91% when compared to GC/MS at the proposed SAMHSA cutoff.