Subjective and physiological effects of intravenous nicotine and cocaine in cigarette smoking cocaine abusers

The subjective and physiological effects of intravenously administered coca ine and nicotine were compared in 10 cigarette-smoking cocaine abusers. Sub jects abstained from smoking at least 8 h before each session. Under double blind conditions, subjects received placebo, cocaine (10, 20, and 40 mg/70 mg), or nicotine (0.75, 1.5, 3.0 mg/70 kg) in mixed order. Physiological a nd subjective data were collected before and repeatedly after each intraven ous drug administration. Subjects also completed a drug Versus money multip le-choice procedure in which they chose between that day's drug and 44 mone tary values. Both drugs increased blood pressure and heart rate and decreas ed skin temperature. Nicotine showed a more rapid onset of subjective effec ts than cocaine. Overall, although both cocaine and nicotine increased subj ective ratings of "drug effect", "rush", "good effects", "liking", "high", and "stimulated", only nicotine increased ratings of "bad effects" and "jit tery". Although the highest nicotine dose produced greater effects than the highest cocaine dose on most subjective measures, the highest cocaine dose produced somewhat greater ratings of drug liking. At doses that produced c omparable ratings of drug effect (40 mg/70 kg cocaine versus 1.5 mg/70 kg n icotine), cocaine produced significantly greater good effects, whereas nico tine produced greater bad effects. All three cocaine doses and the intermed iate and high nicotine doses were frequently categorized as producing effec ts similar to those of cocaine or amphetamine. The drug versus money measur e showed that the highest cocaine dose was worth twice as much as the highe st nicotine dose. Thus, intravenous cocaine and nicotine can be differentia ted by their subjective and reinforcing effects.