A battery of safety evaluations (blood pressure, heart rate, electrocardiogram), 24 visual analog scale ratings to assess subjective effects of cocaine, and safety laboratory tests were conducted and blood samples for pharmacokinetic evaluation of cocaine were collected. The visual analog scales were lines scored to the nearest unit, rating individual items from 0 mm (not at all) to 100 mm (the most ever). Data collected included ratings of feeling "high," "anxious," "confused," "sedated," "good drug effect," "bad drug effect," and "desire to take cocaine." Ratings were obtained at −30, −15, 5, 15, 60, and 90 minutes relative to the intravenous cocaine administration on each test day. Cocaine plasma samples and cardiovascular measures were collected at −15, 5, 15, 30, 45, 60, 90, and 180 minutes relative to cocaine administration. Blood was collected into heparinized tubes prepared with 25 µL of saturated sodium fluoride and 2.5 µL of 10% acetic acid per 1 mL of whole blood. Samples were kept chilled until centrifugation, and plasma was stored at −20°C until analyzed by a validated high-performance liquid chromatography/mass spectroscopic method with a limit of quantitation of 50 ng/mL. Areas under the curve were computed by the trapezoidal rule from 0 to 3 hours.