Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-3-16
pubmed:abstractText
Testing for drugs of abuse in urine is commonplace in emergency departments and neonatal units. However, the clinical sensitivity of immunochemical screening methods is limited by the threshold concentrations used to distinguish between positive and negative specimens. Immunochemical screening methods for cocaine metabolite (benzoylecgonine), cannabinoids, and opiates in urine were recalibrated to detect drugs at lower threshold concentrations. The precision and linearity of the signals at the modified thresholds were verified by diluting drug-positive urine specimens to concentrations below the conventional cutoff concentration and measuring the rate signals in triplicate. To assess the clinical performance of the modified methods, specimens that tested negative using the unmodified assays were re-screened at the lower threshold, and specimens that re-screened positive were submitted for gas chromatographic/mass spectrometric (GC/MS) confirmation. Reproducibility of sub-threshold measurements was comparable to the unmodified assays, and rate separations between successive dilutions were sufficient to give semi-quantitative results. Using the lower thresholds, drugs were detected in 4-5% of the subjects that had screened negative at the conventional threshold concentration. GC/MS analysis confirmed the presence of cannabinoids and cocaine metabolite in 74% and 84%, respectively, of urine specimens that re-screened positive. Morphine, codeine, hydromorphone, or hydrocodone was detected by GC/MS analysis in 31% of opiate-positive re-screens.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0091-7370
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
85-91
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Modification of screening immunoassays to detect sub-threshold concentrations of cocaine, cannabinoids, and opiates in urine: use for detecting maternal and neonatal drug exposures.
pubmed:affiliation
Department of Pathology, University of Florida Health Science Center, Jacksonville 32209, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't