Cocaine is an alkaloid extracted from the leaves of the Erythroxylon coca plant. The plant material has been used for many centuries by the indigenous Indians in South America who chew the coca leaves in their religious ceremonies and as part of everyday dietary practices. The leaves are used to make tea products, such as Health-Inca Tea.
Medicinal Use and Abuse
Cocaine is currently a Schedule II controlled substance and is used by physicians as a vaso-constrictive anesthetic for ophthalmoscopic, oto-laryngological, and trauma surgery. There are no prescription oral medications that contain cocaine; medical use is in the form of cocaine-containing solutions applied topically. Today, cocaine is one of the most commonly abused drugs after ethanol and marijuana It has acquired numerous street names including Blow, Coke, Crack (freebase cocaine), Dust, Flake, Gold Dust, Happy Dust, Lady, Nose, Nose Candy, Rock, Snow, Speedball when mixed with heroin and injected), Stardust, Tick (when smoked with phencyclidine), Toot, and White. The 2006 National Survey on Drug Use and Health estimates that 2.4 million Americans are current users of cocaine 6211}. The 2004 Drug Abuse Warning Network (DAWN) recorded almost 300,000 cocaine-related Emergency Department visits in US hospitals.
Commonly administered by the intranasal and smoking routes, cocaine can also be taken intravenously. The behavioral effects of cocaine are mediated by its ability to block reuptake of dopamine and facilitate its release. Desirable effects of cocaine for the abuser include euphoria especially when smoked or injected), self-confidence, anorexia, hyperactivity and profound sexual excitement. Some users, especially in larger doses, may experience paranoia, hallucinations, and dysphoria. The central stimulators effects “rush” are followed by depression ‘crash’, and it is the positive reinforcement of the rush versus the negative reinforcement of the crash that is the principal reason for the development of chronic cocaine abuse.
Metabolism and Analytical issues
Cocaine is quickly metabolized in the blood and excreted in the urine primarily as benzoylecgonine and, to a lesser extent, ecgonine methyl ester. Only a portion of a dose of cocaine is excreted unchanged in the urine and detection times for the parent drug are short compared with the metabolites that generally can be detected in the urine for 2 to 4 days. Benzoylecgonine is the target analyte of all immunoassays and they also respond to ecgonine methyl ester. GC-MS confirmation is specific to benzoylecgonine. Commonly used local and topical anesthetics, such as lidocaine ‘Xylocaine’ or benzocaine, are structurally unrelated to cocaine and its metabolites and do not result in a positive immunoassay or GC-MS response. Since January 1986, Health-Inca Tea, which contains detectable amounts of cocaine, cannot be legally imported into the United States. Under federal guidelines, MROs cannot accept consumption of cocaine containing tea as a legitimate medical explanation for a positive cocaine test.
Dermal absorption and ‘passive inhalation” of cocaine has been used as explanations for urinary cocaine metabolites in medical workers and law enforcement personnel who claim exposure at work. Published studies, however, do not support this claim.
The MRO, during the verification interview with the donor, should inquire about any recent medical or dental procedures or emergency room visits requiring suturing. If the history is consistent with possible medical use of cocaine within 2 to 3 days of the drug test, the donor should provide a copy of the pertinent medical record.