Subjective and discriminative stimulus effects of two de-nicotinized cigarettes with different tar yields.

The role of tar yield in the subjective and discriminative stimulus effects of cigarette smoking was examined. Current smokers (n=18) smoked two non-nicotine cigarettes with FTC yields of 0.06 mg nicotine and 12.4 mg (low tar) or 17.9 mg tar (high tar). Physiological measures and visual analog scales were completed over a 30-min period. Dosing order was determined randomly and counterbalanced. After sampling both cigarettes, volunteers smoked a third, test cigarette. Half of the volunteers received the low-tar cigarette and half the high-tar cigarette. Volunteers identified the test cigarette (i.e., A or B) at 5, 30, 60, 300, and 900 s after the first puff. Eight of the eighteen participants correctly identified the test cigarette on 4/5 of trials. No significant changes in visual analog scale scores were found among the non-discriminators. However, among discriminators, the low-tar cigarette produced significant positive effects including good drug effects and stimulation relative to the high-tar cigarette. Relative to the low-tar cigarette, the high-tar cigarette produced negative effects including harshness, heaviness, and intensity of flavor. Average tar yield of these participants' usual cigarettes was 9.75 mg, lower than that of the low-tar cigarette used here, possibly accounting for their greater liking of the low-tar cigarette. No changes in blood pressure or heart rate were observed and both cigarettes produced similar carbon monoxide increases, indicating similar depth of inhalation when smoking each. Results suggest cigarette tar yields may play a role in cigarette smoking preferences. Further research is needed to verify whether preferences are maintained after associations with nicotine delivery are extinguished.