Barbiturate is a central nervous system depressant and used as hypnotic sedatives. It is usually taken orally but is sometimes injected intramuscularly and intravenously. Barbiturates are weak acids that are absorbed rapidly from the gastrointestinal tract and are distributed to all tissues and fluids. Short-acting barbiturates are generally excreted in the urine as metabolites, while long-acting barbiturates will primarily be excreted unchanged. Short-acting barbiturates are metabolized entirely by the liver into water-soluble glucuronide compounds, with only 3-6% remaining active before excretion by the kidneys. Studies have shown that heavy dosage may result in severe and/or permanent damage to the human nervous system.
The H&R BAR Test is lateral flow, one-step immunoassay for the qualitative detection of secobarbital in human urine at the following cut-off concentrations:
BAR   300ng/mL.
This test provides only a preliminary analytical test result which should be confirmed by a more specific method. Gas chromatography/mass spectrometry (GC/MS) has been established as the preferred confirmatory method. Clinical consideration and professional judgment should be applied to any drug test result, particularly when preliminary positive results are indicated.