SUBJECTIVE AND CARDIOVASCULAR EFFECTS OF INTRAVENOUS NICOTINE IN SMOKERS AND NONSMOKERS

The present study assessed the subjective and cardiovascular effects o f intravenous nicotine in smokers and nonsmokers. Nonsmokers (n = 5) a nd smokers (n = 5) were administered a single dose of nicotine (0.75 o r 1.5 mg) or saline on each of 3 days. The nicotine doses were given i n ascending order in a double-blind fashion. Although smokers and nons mokers manifested significant increases in systolic and diastolic bloo d pressure and heart rate 1 min after administration of all active tes t doses, the difference between peak heart rate and that measured at l ater times was greater in nonsmokers than in smokers. Nonsmokers and s mokers also differed in subjective self-reports. In response to items on visual analogue scales indicative of positive effects (e.g., ''good effects,'' ''like drug,'' ''use again,'' and ''feel energetic''), smo kers but not nonsmokers reported high scores (> 40) after nicotine inj ection. In addition, responses on the MBG and LSD subscales of the Add iction Research Center Inventory indicated that smokers experienced po sitive subjective effects after the test doses, whereas nonsmokers exp erienced disorientation. The fact that intravenous nicotine was not as sociated with positive subjective effects in nonsmokers indicates that repeated exposure is required to establish positive reinforcing effec ts of nicotine.