Journal of analytical toxicology
-
Comparative Study
A comparative evaluation of the instant-view 5-panel test card with OnTrak TesTcup Pro 5: comparison with gas chromatography-mass spectrometry.
This study compared the ability of two on-site testing devices, Instant-View Test Card and OnTrak TesTcup Pro 5, to discriminate negative from positive urine samples for cannabinoids, cocaine metabolite, opiates, amphetamines, and benzodiazepines. The on-site devices were evaluated in a precision study with fortified urine samples and in a clinical study with samples submitted for forensic urine drug testing. For precision, seven stocks were prepared per device. ⋯ The clinical study revealed that the Instant-View Test Card had low cross-reactivity (i.e., false negatives) for samples with amphetamine only and oxycodone. TesTcup had low cross-reactivity for samples with amphetamine only and hydrocodone and/or hydromorphone; it also had more cross-reactivity towards (i.e., false positives) sympathomimetic amines. In summary, the Instant-View Test Card was less precise than the TesTcup at or near the cutoff; with clinical samples, however, the percent accuracies of the two devices were similar.
-
Evidence of morphine metabolism to hydromorphone in pain patients chronically treated with morphine.
Minor metabolic pathways in human subjects have been shown to exist for the conversion of codeine to hydrocodone but have not been reported for the metabolic conversion of morphine to hydromorphone. In this study, urine specimens were collected in an out-patient setting from 13 pain patients who were chronically treated with morphine and other opioids (methadone, oxycodone, and fentanyl). The chronic pain patients were chosen for study because they were treated with high-dose morphine and had no personal or family history of addiction. ⋯ Concentrations of hydromorphone in this patient were in the range of 3400-13,000 ng/mL, while concurrent morphine concentrations were in the range of 3200-6600 ng/mL. These data are highly suggestive that hydromorphone can be produced as a minor metabolite of morphine in humans. Although additional studies in more restricted settings are needed, it is recommended that interpretation of low urinary concentrations of hydromorphone in combination with high concentrations of morphine in morphine-treated pain patients should not be considered as conclusive evidence of hydromorphone misuse.