Cocaine use is most prevalent in North and South America, and increasingly in Western Europe, especially among urban men aged 15 to 35 years. It is the illegal drug most often associated with emergency department visits in the US.

Up to one in six persons who use cocaine will become dependent; abuse liability is greater with intravenous and smoked cocaine, compared to intranasal and oral use. Cocaine base has a low melting point and can be smoked; cocaine salt is water soluble and can be injected or absorbed across mucous membranes.

Cocaine is largely metabolized to inactive hydrolytic products in the liver and plasma. Use of alcohol with cocaine produces a new metabolite, cocaethylene, which has actions similar to cocaine but a longer half-life. Concurrent alcohol use with cocaine may cause more severe and longer lasting toxic effects.

Drug testing detects the metabolite benzoylecgonine, which is usually detectable two to four days after the last cocaine use, although this can be up to 14 days after heavy, prolonged use.

Cocaine use increases energy and alertness, can produce euphoria, and decreases appetite and need for sleep. Adverse effects may include anxiety, irritability, paranoia, delusions, and hallucinations. These may be accompanied by tachycardia, diaphoresis, nausea, and pupil dilatation. There is poor correlation between cocaine plasma concentrations and toxicity.

Withdrawal symptoms from chronic cocaine use are predominantly psychological: depression, anxiety, anhedonia, cocaine craving, and increased sleep. Most symptoms are self limited and resolve within one to two weeks..

Effects of cocaine on specific organ systems are:

    - CNS: seizures, stroke, movement disorders
    - Cardiovascular: myocardial infarction, arrhythmia, cardiomyopathy, and myocarditis
    - Respiratory: rhinitis and septal perforation (with intranasal use) cough, wheeze, chest pain (with smoked use)
    - GI: xerostomia, gastric ulcers, ischemic colitis

Acute cocaine intoxication is treated with supportive care (ART: acceptance, reassurance, talkdown); benzodiazepines may be required to control severe agitation. Hospitalization may be indicated for psychotic symptoms or agitation that does not respond; symptoms that persist beyond a few days suggest an etiology other than cocaine use..

Treatment for cocaine addiction occurs primarily in the outpatient setting, and involves psychosocial treatment. Rates for long-term abstinence are less than 50 percent. Buprenorphine may be helpful for patients who are co-addicted to opiates; disulfiram, topiramate, tiagabine, and modafinil have shown some promise for cocaine abstinence. Peer group self-help programs (such as Cocaine Anonymous) improve outcomes.

Acknowledgment — Preparation of this topic was supported by the
Intramural Research Program of NIH, National Institute on Drug Abuse.

Author
David A Gorelick, MD, PhD

Deputy Editor
H Nancy Sokol, MD

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