Study to Improve Scientific Understanding of the Cardiovascular Actions of Cocaine

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