Benzodiazepines are central nervous system depressant drugs often detected in
biological samples from driving under the influence (DUI) offenders. They are associated with marked
psychomotor impairment and represent up to 20% of all Miami-Dade County, Florida DUI urine samples analyzed in our laboratory annually.
Flunitrazepam emerged in the mid-1990s as an
illegal drug in the U.S. that was predominantly abused recreationally and associated with sexual assaults. Immunoassays for
benzodiazepines do not discriminate between different
benzodiazepines, and certain metabolites, such as
7-aminoflunitrazepam, react poorly with immunoassay
reagents. A simple and sensitive method for the detection and quantitation of major
benzodiazepines and metabolites by gas chromatography with mass selective detection is presented. This method was used to confirm
benzodiazepines in general and
flunitrazepam in particular. Data collected over a three-and-a-half-year period are summarized. Whereas
flunitrazepam was present in up to 10% of DUI cases in 1995 and 1996 and had fast become the most frequently encountered
benzodiazepine in Miami-Dade County DUI-related urine samples, a dramatic drop in case numbers followed the legal reclassification of the
drug as a Schedule I substance in Florida in February 1997.
Flunitrazepam was often used alone or in combination with cannabis and
cocaine. A recent rise in
clonazepam cases coincides with the decrease in
flunitrazepam confirmation and may indicate a new trend in the abuse of
benzodiazepines in South Florida.