Cocaine is used by more than 13 million people worldwide, about 0.3 percent of the global population age 15 to 64 years.
Cocaine is used by more than 13 million people worldwide, about 0.3 percent of the global population age 15 to 64 years. Use and abuse are most prevalent in North America (6.3 million people, 2 percent of population older than 14 years) and South America (2.7 million people, 0.94 percent) and in Western Europe (3.4 million people, 1 percent). Current use in the United Kingdom and Spain has reached the levels of the US. There is relatively little cocaine use in Africa, Asia, Eastern Europe, and Oceania. This pattern may be due to supply rather than demand factors, because of the difficulty in obtaining cocaine from its only source in South America and the ready availability of alternative synthetic stimulants such as amphetamines.Most cocaine use is by urban men age 15 to 35 years. About 126,000 (6.2 percent) current users in the US are adolescents 12 to 17 years old. Cocaine use has declined somewhat among this age group in the last few years, but has remained steady in older groups. More than one-quarter of past year cocaine users (more than 1.5 million) meet psychiatric diagnostic criteria for cocaine abuse or dependence. Yet in 2004, only 884,000 cocaine users received substance use treatment.
Cocaine is the illegal drug most often associated with visits to US hospital emergency departments. In 2005, it was involved in an estimated 31 percent of drug-related emergency department visits (about 450,000 visits), versus about 17 percent (240,000 visits) for marijuana and about 11 percent (165,000 visits) for heroin. Almost one-fifth of cocaine-related visits were by patients seeking detoxification; 3.2 percent were for suicide attempts.
Patterns of use — Cocaine is used in a variety of patterns. The typical “binge” involves short periods of heavy use (eg, payday or weekends) separated by longer periods of little or no use. Others may use for an extended period until their finances are exhausted or access to cocaine is interrupted. A small number of users who are self-medicating an underlying neuropsychiatric disorder, such as attention deficit hyperactivity disorder (ADHD) or narcolepsy, may use low doses daily without dose escalation over time. Most cocaine users living in the community do not use very frequently. Half (49.1 percent) of past year users used less than 12 times in the year; only 2.5 percent used at least 300 times.
Risk factors for use and abuse — While cocaine use occurs in all sociodemographic groups, it is not equally distributed among the US population. The highest prevalence of use is among unemployed men in their 20s with no more than a high school education who live in urban areas. Cocaine use is highly associated with use of other legal and illegal substances and with psychiatric disorders. Cigarette smokers and heavy alcohol drinkers are 10 times more likely than others to be cocaine users. Among current (past month) cocaine users, 92 percent use alcohol and 79 percent smoke cigarettes (73 percent use both). Almost half are heavy drinkers (five or more drinks on the same occasion on at least five days in the past 30 days). Concurrent use of cocaine and alcohol produces a new compound, cocaethylene, which is pharmacologically active. Many cocaine users use other substances either to enhance the “high” (eg, simultaneous use of opiates ["speedballing"]) or to ameliorate adverse effects of intoxication or withdrawal (eg, use of alcohol, cannabis, or benzodiazepines). Current cocaine users are twice as likely as non-users to have symptoms of depressive or anxiety disorders. Among past year cocaine users, almost one-quarter reported serious psychological distress during that year.
Cocaine users are at high risk for abuse or dependence. Community-based interview surveys suggest that up to one in six persons who use cocaine will become dependent. Heavier users and users who take the drug intravenously or by smoking are more likely to become dependent than lighter users or intranasal and oral users. The greater abuse potential of intravenous or smoked cocaine is attributed to the faster rate of drug delivery to the brain (within 10 seconds), and faster onset of psychological effects. This faster onset is associated with a more intense pleasurable response (the so-called “rate hypothesis” of psychoactive drug action).
The environment (including family, religious, and social factors) has the strongest influence on initial cocaine use. Studies of drug use by pairs of fraternal (dizygotic) and identical (monozygotic) twins suggest a significant genetic influence on the risk of developing cocaine abuse or dependence after use has begun. Several promising candidate genes have been identified, including those for dopamine receptors and the dopamine transporter, but no specific gene has been clearly linked with cocaine addiction. Cocaine enhances monoamine neurotransmitter (dopamine, norepinephrine, and serotonin) activity in the central and peripheral nervous systems by blocking the presynaptic reuptake pumps (transporters) for these neurotransmitters. Cocaine’s positive psychological effects and abuse liability are considered to be due to its enhancement of brain dopamine activity, especially in the so-called corticomesolimbic dopamine reward circuit. Thus, cocaine addiction has been termed a disease of the brain’s dopamine reward system.
Cocaine is unique among stimulant drugs in having a second action of blocking voltage-gated membrane sodium ion channels. This action accounts for its local anesthetic effect, and may contribute to cardiac arrhythmias.
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