The abuse of cocaine and other psychostimulants reflects a complex interaction between the pharmacology of the drug, the personality and expectations of the user, and the environmental context in which the drug is used. Polydrug abuse involving the concurrent use of several drugs with different pharmacologic effects is increasingly common. Sometimes one drug is used to enhance the effects of another, as with the combined use of cocaine and nicotine, benzodiazepines and methadone, or cocaine and heroin in methadone-maintained patients. Some forms of polydrug abuse, such as the combined use of IV heroin and cocaine, are especially dangerous and account for many hospital emergency room visits.
Chronic cocaine and psychostimulant abuse may cause a number of adverse health consequences and may exacerbate preexisting disorders such as hypertension and cardiac disease. The combined use of two or more drugs may accentuate medical complications associated with abuse of one drug. Chronic drug abuse is often associated with immune system dysfunction and increased vulnerability to infections, including risk for HIV infection. In addition, concurrent use of cocaine and opiates (the “speedball”) is frequently associated with needle sharing by IV drug users. IV drug abusers continue to be the largest single group of persons with HIV infection in several major metropolitan areas in the United States as well as in many parts of Europe and Asia.
Stimulants and hallucinogens have been used to induce euphoria and alter consciousness for centuries. Cocaine and marijuana are two of the most commonly abused drugs today. Synthetic variations of marijuana and a variety of hallucinogens have become popular recently, and new drugs are continually being developed. This chapter describes the subjective and adverse medical effects of cocaine, marijuana, and lysergic acid diethylamide (LSD), as well as methamphetamine, 3,4-methylenedioxy-N-methamphetamine (MDMA), synthetic cathinones (bath salts), phencyclidine (PCP), Salvia divinorum, and other drugs of abuse (flunitrazepam, γ-hydroxybutyric acid [GHB], ketamine). Some options for medical management of severe adverse effects are also described.
Cocaine is a stimulant and a local anesthetic with potent vasoconstrictor properties. The leaves of the coca plant (Erythroxylum coca) contain ~0.5–1% cocaine. The drug produces physiologic and behavioral effects after oral, intranasal, IV, or inhalation/smoking routes of administration. The reinforcing effects of cocaine are related to activation of dopaminergic neurons in the mesolimbic system (Chap. 465e). Cocaine increases synaptic concentrations of the monoamine neurotransmitters dopamine, norepinephrine, and serotonin by binding to transporter proteins in presynaptic neurons and blocking reuptake.
PREVALENCE OF COCAINE USE
Cocaine is widely available and is abused in virtually all social and economic strata of society. In 2012, an estimated 1.6 million persons in the United States used cocaine, and 1.1 million abused or were dependent on cocaine. Emergency room admissions involving cocaine totaled 505,224 in 2011. Cocaine abuse is prevalent in the general population and in heroin-dependent persons, ...