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High
doses of cocaine can cause euphoric excitement or schizophrenic-like
symptoms. Psychologic and physical dependence can lead to profound
addiction.
Most cocaine users are episodic recreational users who voluntarily curtail their use. However, cocaine use and the development of addictive behavior in some users has increased in North America, although recent declines are recorded. Availability of highly biologically active forms, such as crack cocaine, has worsened the problem of cocaine dependence.
Although most cocaine in the US is snorted, smoking crack cocaine has become widely publicized. The hydrochloride salt is converted to a more volatile form, usually by adding NaHCO3, water, and heat. The converted material is combusted and the resultant smoke inhaled. Onset of effect is quicker, and intensity of the high is magnified. Crack use has not expanded to the suburbs or to the urban middle class: Low-income Americans continue to be the primary users.
Tolerance to cocaine occurs, and withdrawal from heavy use is characterized by somnolence, increased appetite, and depression. The tendency to continue taking the drug is strong after a period of withdrawal.
Symptoms and Signs
Acute use:
Effects differ with different modes of use. When injected or smoked, cocaine produces hyperstimulation, alertness, euphoria, and feelings of competence and power. The excitation and high are similar to those produced by injecting amphetamine. These feelings are less intense and disruptive in users who snort cocaine powder.
An overdose may produce tremors, seizures, and delirium. Death may result from MI, arrhythmias, and heart failure. Patients with extreme clinical toxicity may, on a genetic basis, have decreased (atypical) serum cholinesterase, an enzyme needed for clearance of cocaine. The concurrent use of cocaine and alcohol produces a condensation product, cocaethylene, which has stimulant properties and may contribute to toxicity.
Chronic use:
Because cocaine is a very short-acting drug, heavy users may inject it or smoke it q 10 to 15 min. This repetition produces toxic effects, such as tachycardia, hypertension, mydriasis, muscle twitching, sleeplessness, and extreme nervousness. Hallucinations, paranoid delusions, and aggressive behavior may develop, which can make the person dangerous. Pupils are maximally dilated, and the drug's sympathomimetic effect increases heart and respiration rates and BP.
Severe toxic effects occur in the compulsive heavy user. Rarely, repeated snorting causes nasal septal perforation due to local ischemia. Repeatedly smoking volatile crack cocaine in high doses can have serious toxic cardiovascular and behavioral consequences.
Treatment
Treatment of acute cocaine intoxication is generally unnecessary because the drug is extremely short-acting. If an overdose requires intervention, IV barbiturates or diazepam may be used, but close observation and supportive care is the appropriate approach. Anticonvulsants do not prevent seizures due to cocaine overdose. Hyperthermia or significantly elevated BP, which rarely results, must be treated.
Stopping sustained use requires considerable assistance, and the depression that may result requires close supervision and treatment. Many nonspecific therapies, including support and self-help groups and cocaine hotlines, exist. Extremely expensive inpatient therapy is available.
Treatment of infants born to cocaine-addicted mothers is discussed in Metabolic, Electrolyte, and Toxic Disorders in Neonates: Prenatal Drug Exposure.
Last full review/revision November 2005
Content last modified November 2005
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