Journal of analytical toxicology
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Multicenter Study Comparative Study Clinical Trial
A multiple-site laboratory evaluation of three on-site urinalysis drug-testing devices.
Presented are findings from a multisite laboratory evaluation comparing on-site urinalysis drug-test results to results from Syva EMIT immunoassay and gas chromatography-mass spectrometry (GC-MS). Three laboratories participated in the NHTSA-funded project. Specimens were tested for amphetamines, benzodiazepines, cocaine, cannabinoids, and opiates. ⋯ It also required an investigation of each discrepant result-a consideration not taken in many previous evaluations of on-site testing devices. Compared with current federal guidelines for workplace urinalysis testing, more donor samples would screen positive for cannabinoids and cocaine by the on-site devices than by EMIT immunoassay. However, fewer would be reported as positive because most contained GC-MS-determined drug concentrations lower than the federal confirmation and reporting limits.
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Comparative Study Clinical Trial Controlled Clinical Trial
Oxaprozin cross-reactivity in three commercial immunoassays for benzodiazepines in urine.
Immunoassay methods are commonly used to screen for drugs of abuse and some prescription drug classes as part of drug-testing programs in clinical and forensic toxicology. Oxaprozin (Daypro) is a new nonsteroidal anti-inflammatory drug that is widely prescribed in North America and has been reported to cross-react for benzodiazepines in several different immunoassay methods. The first objective of this study was to characterize the immunoreactivity of oxaprozin standards over a wide concentration range when analyzed by the EMIT dau, Abbott FPIA, and BMC CEDIA urine benzodiazepine assays. ⋯ With a 200-ng/mL cutoff for benzodiazepines in these assays, all 36 urine specimens collected from the 12 subjects gave positive results by EMIT and CEDIA, and 35 of 36 urine specimens were positive by FPIA. It was concluded that presumptive positive benzodiazepine results by these immunoassays may be due to the presence of oxaprozin or oxaprozin metabolites. It is recommended that all positive immunoassay screening tests for benzodiazepines be confirmed by another technique based upon a different principle of analysis.
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Tramadol is a centrally acting, binary analgesic that is neither an opiate-derived nor a nonsteroidal anti-inflammatory drug and that was approved for use in the United States in 1995. It is used to control moderate pain in chronic pain settings such as osteoarthritis and postoperative cases. Used in therapy as a racemic mixture, the (+)-enantiomer weakly binds to the mu-opioid receptor, and both enantiomers inhibit serotonin and norepinephrine reuptake. ⋯ Analysis of 12 blood samples from tramadol-related deaths and four nonfatal intoxications involving tramadol revealed concentrations ranging from 0.03 to 22.59 mg/L for tramadol, from 0.02 to 1.84 mg/L for ODT, and from 0.01 to 2.08 mg/L for N-desmethyltramadol. Three deaths were clearly attributable to acute morphine toxicity, one was a doxepin overdose, and six were multiple drug overdoses. The role of tramadol in each death is explored.
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Gas chromatographic-mass spectrometric (GC-MS) quantitation of 25 cannabis sed oils determined delta 9-tetrahydrocannabinol (THC) concentrations from 3 to 1500 micrograms/g oil. In a pilot study, the morning urine of six volunteers who had ingested 11 or 22 g of the oil, which contained the highest THC content (1500 micrograms/g), was collected for six days. ⋯ Urine samples were found cannabis positive for up to six days with THCCOOH-equivalent concentrations up to 243 ng/mL. by the Abuscreen OnLine immunoassay and THCCOOH contents from 5 to 431 ng/mL by the GC-MS method. All subjects reported THC-specific psychotropic effects.
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A commercially available health food product of cold-pressed hemp seed oil ingested by one volunteer twice a day for 4 1/2 days (135 mL total). Urine specimens collected from the volunteer were subjected to standard workplace urine drug testing procedures, and the following concentrations of 11-nor-delta9- tetrahydrocannabinol carboxylic acid (9-THCA) were detected: 41 ng/mL 9-THCA at 45 h, 49 ng/mL at 69 h, and 55 ng/mL at 93 h. ⋯ Four subsequent specimens taken to 177 h were also negative. This study indicates that a workplace urine drug test positive for cannabinoids may arise from the consumption of commercially available cold-pressed hemp seed oil.