The researchers discovered that cocaine elevates body temperature by impairing the body's ability to increase skin-blood flow, to sweat and to perceive excessive heat stress. The findings appear in today's issue of Annals of Internal Medicine.

"Individuals who abuse cocaine, especially in hot temperatures while participating in recreational sports or attending rave parties, won't perceive that they are hot and are, therefore, less likely to drink water or to find cooler conditions," said Dr. Craig Crandall, assistant professor of internal medicine and lead author of the study. "The hyperthermic effects of cocaine are greatly amplified when the drug is used under these conditions.

"This may result in serious heat-related injuries, including heat cramps, heat exhaustion, heat stroke and ultimately death," added Crandall, who is also a research scientist at the Institute for Exercise and Environmental Medicine, a joint venture between UT Southwestern and Presbyterian Hospital of Dallas.

Crandall and his collaborators studied the mechanism of cocaine-induced hyperthermia in seven volunteers who had never used cocaine. The researchers compared the effects of a small dose of cocaine dissolved in saline solution and a placebo. Both were applied to the inside of the nose of each of the study volunteers in separate trials. The researchers measured esophageal temperature, skin-blood flow, sweat rate and perceived thermal sensation.

Approximately 25 million Americans have tried cocaine, which is a major cause of life-threatening cardiovascular emergencies, including hypertensive crisis, acute myocardial infarction and ventricular arrhythmias. Cocaine is t
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Contact: Amy Shields
Amy.Shields@UTSouthwestern.edu
214-648-3404
UT Southwestern Medical Center
3-Jun-2002