Benzodiazepine Screening Using EMIT II® and TDx®: Urine Hydrolysis Pretreatment Required*

Urine specimens were collected from individuals prescribed oral doses of the following benzodiazepine tablets: diazepam, oxazepam, temazepam, lorazepam, alprazolam, flurazepam, and chlordiazepoxide. An aliquot was hydrolyzed using Helix pomatia beta-glucuronidase. Both the hydrolyzed and unhydrolyzed urine pairs were subjected to EMIT II and TDx immunoassay screening tests and to gas chromatographic-mass spectrometric quantitation. Hydrolysis is required to ensure adequate detection of oxazepam, temazepam, and lorazepam with either screening method. A 100-ng/mL cutoff is required when screening for lorazepam, following therapeutic doses. The EMIT II is more sensitive than the TDx as a screening test for benzodiazepines.