Study to Improve Scientific Understanding of the Cardiovascular Actions of Cocaine

Cocaine and Sympathetic Nerve Activity in Humans

The purpose of this study is to improve the scientific understanding of the cardiovascular actions of cocaine, in particular the ability of cocaine to increase blood pressure.

Cocaine abuse has emerged as a major cause of life-threatening cardiovascular emergencies but our understanding of the underlying mechanisms mediating the adverse effects of cocaine is far from complete. Our previous studies in cocaine-naive human subjects have demonstrated that intranasal cocaine acutely stimulates the human cardiovascular system by a novel central mechanism of action.We are currently investigating a central sympatholytic drug,dexmedetomidine, in reversing the sympathomimetic effects (increase in blood pressure, heart rate and coronary vasoconstriction) of intranasal cocaine.This drug may be a new pharmacologic agent in the treatment of acute cocaine intoxication in humans.

Inclusion Criteria:

• Cocaine naive healthy volunteers

Exclusion Criteria:

• Any evidence of cardiopulmonary disease by history or physical examination
• History of hypertension or 24 hour blood pressure averaging >135/85 mmHg
• Any history of substance abuse (other than tobacco)
• Diabetes mellitus or other systemic illness
• Individuals with a history of pseudocholinesterase deficiency
• Pregnancy