ALLEVIATION OF COCAINE-INDUCED CORONARY VASOCONSTRICTION BY NITROGLYCERIN

Cocaine induces vasoconstriction of epicardial coronary arteries in patients with and without coronary artery disease, and this vasoconstriction is particularly marked in segments narrowed by atherosclerosis. To assess the effect of nitroglycerin on cocaine-induced coronary vasoconstriction, computer-assisted quantitative analysis was performed on nondiseased and diseased coronary artery segments in 23 patients (18 men, 5 women, aged 43 to 65 years) 1) at baseline, 2) after administration or intranasal saline solution (in 8 patients) or 2 mg/kg of cocaine (in 15 patients), and then 3) after administration of sublingual placebo (in 6 patients) or 0.4 or 0.8 mg of nitroglycerin (in 9 patients) in the 15 patients given cocaine. In response to cocaine administration, coronary artery cross-sectional area decreased 22 +/- 7% (mean +/- SD) in nondiseased segments (p < 0.05) and 45 +/- 18% in diseased segments (p < 0.02). The magnitude of vasoconstriction was greater (p = 0.01) in the diseased segments. Sublingual nitroglycerin abolished the vasoconstriction in both nondiseased and diseased segments. Thus, nitroglycerin alleviates cocaine-induced vasoconstriction in patients with coronary artery disease.