A solid-phase extraction and GC-MS confirmation method was developed for certain urinary diazolo- and triazolobenzodiazepines, including the metabolites of lorazepam, clonazepam, alprazolam, and triazolam. The latter two do not form benzophenones, and the others are not readily confirmed by conventional thin-layer chromatography or GC-MS techniques. Samples were hydrolyzed with glucuronidase at 37 degrees C, adjusted to pH 4.5, extracted with Bond Elut Certify columns, dried, and derivatized using BSTFA with 1% TMCS. Sample preparation time averaged 4 hours. A GC-MS selected-ion-monitoring acquisition method targeting retention time, molecular ion abundances, and qualifier ion ratios was used to determine positive results. The recovery of 7-NH2-clonazepam was 95%, and recoveries of alpha-hydroxyalprazolam, alpha-hydroxytriazolam, and lorazepam were greater than 66%. Linearity was demonstrated from 0.1 to 1.0 microgram/mL for each drug. Within-run CVs were less than 11%, and between-run CVs were less than 16%. Using this technique, we have been able to confirm suspected cases of abuse that had not been confirmed by previous techniques.

Opiate toxicology testing is routinely performed in the hospital setting to identify abusers and/or to determine those patients who are not taking prescribed opiate analgesics such as oxycodone. Commercially available assays for opiate detection in urine have decreased sensitivity for oxycodone, which contributes to a high false-negative rate. Functioning as a beta site, our Veterans Affairs hospital evaluated a new enzyme immunoassay, DRI Oxycodone Assay, for its use in the qualitative and semiquantitative detection of oxycodone in urine. We hypothesize that an immunoassay for oxycodone with superior sensitivity and specificity, when compared to the traditional opiate assays, would reduce the need for more expensive and time-consuming confirmatory testing. We used the new liquid homogenous enzyme immunoassay to determine oxycodone results in a total of 148 urine samples from 4 different sample groups. Gas chromatography-mass spectroscopy was subsequently used to confirm the presence or absence of oxycodone (or its primary metabolite, noroxycodone). We also evaluated within-run, between-run, and linearity studies and conducted a crossover study to establish a cutoff value for oxycodone. In our patient population, we used the new DRI immunoassay to evaluate 17,069 urine samples to estimate oxycodone misuse profiles (patients not taking prescribed oxycodone or taking oxycodone without a prescription) during a 4-month period. The sensitivity and specificity of the new oxycodone immunoassay were 97.7% and 100%, respectively, at the cutoff concentration of 300 ng/mL. The assay linearity was 1,250 ng/mL, and the sensitivity was 10 ng/mL. Within-run precision and between-run coefficient of variation were 2.3% and 1.8%, respectively. None of the 15 compounds that we evaluated for interference had crossover significant enough to produce a positive oxycodone result when using 300 ng/mL as the cutoff value. None of the 17,069 oxycodone immunoassays was followed with a request for confirmation. Among patients with positive results (n = 224), 93 (41.5%) were not prescribed oxycodone. The new DRI Oxycodone Assay is a sensitive and specific screening test for the determination of oxycodone. The improved opiate screening results may lead to better patient and prescription management, to decreased laboratory spending, and to the identification of oxycodone abusers, which could result in decreased oxycodone-related mortality.

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