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Medline ® Abstract for Reference 42

of 'MDMA (ecstasy) intoxication'

Influence of labetalol on cocaine-induced coronary vasoconstriction in humans.
Boehrer JD, Moliterno DJ, Willard JE, Hillis LD, Lange RA
Am J Med. 1993;94(6):608.
PURPOSE: Although labetalol is sometimes given to patients with cocaine-associated chest pain, its influence on cocaine-induced coronary vasoconstriction is unknown.
PATIENTS AND METHODS: In 15 patients (7 men, 8 women, aged 40 to 79 years) undergoing catheterization for chest pain, heart rate, mean arterial pressure, and coronary arterial area (by computer-assisted quantitative angiography) were measured (1) at baseline, (2) 15 minutes after intranasal cocaine, 2 mg/kg, then (3) 5 minutes after intravenous saline (n = 6) or labetalol, 0.25 mg/kg (n = 9).
RESULTS: Of 40 coronary arterial segments analyzed, cocaine induced a 13% +/- 10% (mean +/- standard deviation) decrease in coronary arterial area in 32. Subsequently, no variable changed after saline administration. Although labetalol reduced mean arterial pressure (117 +/- 14 mm Hg after cocaine, 110 +/- 11 mm Hg after labetalol; p<0.05), it induced no change in the coronary arterial area (3.47 +/- 1.37 mm2 after cocaine, 3.37 +/- 1.32 mm2 after labetalol; p = NS).
CONCLUSION: Labetalol reverses the cocaine-induced rise in mean arterial pressure, but does not alleviate cocaine-induced coronary vasoconstriction.
Department of Internal Medicine (Cardiovascular Division), University of Texas Southwestern Medical Center, Dallas 75235.