Cardiovascular Complications of Cocaine Use

The deaths of several celebrities in recent years in association with the nontherapeutic use of cocaine have focused widespread attention on the problem of cocaine abuse. In 1999, an estimated 25 million Americans admitted that they had used cocaine at least once; 3.7 million had used it within the previous year; and 1.5 million were current users. During the same year, cocaine was mentioned in 30 percent of all drug-related visits to emergency departments. Cocaine is the most commonly used illicit drug among subjects seeking care in hospital emergency departments or drug-treatment centers. In addition, it is the most frequent cause of drug-related deaths reported by medical examiners.

Cocaine use rose to epidemic levels in the early and mid-1980s, after which it declined in prevalence. However, between 1994 and 1998, the number of new cocaine users per year increased 82 percent, from 514,000 to 934,000. Several factors account for this recent increase in cocaine use, including the ease of its administration, the increased availability and purity of the drug, reduced cost, and the misperception that the recreational use of cocaine is safe. In a recent survey conducted by the Department of Health and Human Services, only 50 percent of young people expressed the belief that monthly cocaine ingestion carries a great risk of harm. In fact, as cocaine abuse has become widespread, the number of cocaine-related cardiovascular events, including angina pectoris, myocardial infarction, cardiomyopathy, and sudden death from cardiac causes, has increased dramatically.

Pharmacology and Mechanisms of Action

Cocaine (benzoylmethylecgonine) is an alkaloid extracted from the leaf of the Erythroxylon coca bush, which grows primarily in South America. It is available in two forms: the hydrochloride salt and the "free base." Cocaine hydrochloride is prepared by dissolving the alkaloid in hydrochloric acid to form a water-soluble powder or granule that decomposes when heated. It can be taken orally, intravenously, or intranasally, the slang terms for which are "chewing," "mainlining," and "snorting," respectively. The free-base form is manufactured by processing the cocaine with ammonia or sodium bicarbonate (baking soda) to remove the hydrochloride. This form is heat-stable and melts at 98°C, which allows it to be smoked. It is known as "crack" because of the popping sound it makes when heated.

Since cocaine hydrochloride is well absorbed through all mucous membranes, abusers may achieve a high blood concentration by means of intranasal, sublingual, intravaginal, or rectal administration. As compared with the intravenous injection of cocaine, the mucosal administration of the drug results in a slower onset of action, a later peak effect, and a longer duration of action. Euphoria occurs within seconds after crack cocaine is smoked and is short-lived. Crack cocaine is considered to be the most potent and addictive form of the drug.