EFFECTS OF ACUTE INTRAVENOUS COCAINE ON CARDIOVASCULAR FUNCTION, HUMAN LEARNING, AND PERFORMANCE IN COCAINE ADDICTS

Continuous non-invasive cardiovascular monitoring in eight healthy coc aine addicts receiving intravenous cocaine (0.325 mg/kg or 0.650 mg/kg ) or placebo in double-blind, randomized, cross-over fashion demonstra ted significant dose-dependent increases in pulse and mean arterial pr essure following cocaine. Pulse and mean arterial pressure peaked 5 mi n post-cocaine injection and maximal response was sustained for a furt her 15 min and 35 min afterwards, respectively. Cocaine administration had no significant effect on peripheral oxygen saturation, and no cli nically significant abnormalities of rhythm or conduction were seen on the electrocardiogram. These doses and method of single-dose intraven ous cocaine administration, and our procedures for cardiovascular moni toring, appear relatively safe for laboratory studies of healthy cocai ne addicts with no pre-existing cardiovascular disease. In addition, c ocaine-taking (0.325 mg/kg i.v. and 0.650 mg/kg i.v.) was associated w ith enhanced attention (i.e. increased numbers of correct responses on the Rapid Visual Information Processing Task), but the trend towards reduced reaction time did not achieve statistical significance. Cocain e-taking resulted in a small but statistically insignificant improveme nt in learning on the Digit Symbol Substitution Task. These results su ggest that cocaine-taking in rested subjects is associated with some c ognitive enhancement. (C) 1998 Elsevier Science Ireland Ltd.