LACK OF CROSS-REACTIVITY OF AMBIEN (ZOLPIDEM) WITH DRUGS IN STANDARD URINE DRUG SCREENS

Objective.-To determine in healthy volunteers (men and women; 18 to 40 years old) the potential cross-reactivity of Ambien (zolpidem) and/or its metabolites with drugs that are screened by the Syva EMIT II and the Abbott AD(X) urine drug screens assays. Design.-Open-label, fixed- treatment sequence of 1 night each of treatment with zolpidem (10 mg) and temazepam (15 mg). Setting.-Clinical Pharmacology Unit within a te aching hospital. Main Outcome Measures.-Over a 24-hour period, presenc e or absence of positive results on the Syva EMIT II or the Abbott AD( X), urine drug assay system, each performed at two different laborator y assay sites. Results.-Following ingestion of zolpidem, no subject ha d any positive response in either laboratory to the Syva EMIT II or th e Abbott AD(X) urine drug screen assays at 0, 4, 8, 12, and 24 hours p ostdose. During the same time period, all subjects had measurable zolp idem plasma concentrations at 1.5 and 8 hours postdose, with mean conc entrations of 115.2 ng/mL and 30.1 ng/mL, respectively (in agreement w ith its half-life of 2.5 hours). The positive response rate at 10 hour s after ingestion of Restoril (temazepam) among the four laboratory/as say combinations ranged from 36.8% to 73.7%, a range that is within th e reported response rates for these tests. Conclusions.-These data ind icate that zolpidem will not cross-react in standard urine drug screen s with benzodiazepines, opiates, barbiturates, cocaine, cannabinoids, or amphetamines.