Toxicology Laboratories
Cocaine is one of the most abused drugs in the United States. Isolated in 1859 and brought to attention through a series of papers by Dr. Sigmund Freud, cocaine was subsequently adopted as a useful topical anesthetic. Its non prescriptive use was illegalized by the Harrison Act of 1914.
Pharmacological Effects
Generally, 50-100 mg of cocaine is necessary for intranasal “snorting” associated with a “high”. Cocaine injected intravenously is often mixed with heroin, referred to as “speed balling”. Cocaine, in the form of a very pure free base, “crack” is smoked in a pipe. The more direct and concentrated the route of administration, the faster habituation occurs. Euphoric feelings produced by cocaine eventually give way to depression, paranoia, habituation, and other dysfunctions. Primates (monkeys), given the choice between cocaine and food, have died while continuously choosing cocaine. Clearly a dangerous drug, cocaine is not a cheap or easy high, has serious addictive properties, and societal consequences.
Laboratory Methods
Cocaine and its primary metabolite benzoylecgonine are routinely detected by a variety of laboratory techniques. Some Laboratories utilize the immunoassays for initial screening with confirmation of positives by gas chromatography/mass spectrometry (GC/MS).
Cutoff and Detection Post Dose
The initial screening cutoff level is 300 ng/ml for cocaine and its metabolite benzoylecgonine. Use of cocaine for euphoria may result in positive urines above this level for 48-72 hours post dose. Longer times will be observed in the habituated person using large quantities. The GC/MS cutoff level is 150 ng/ml.
Daniel Redwood DC
Tom Ferguson MD
