Disposition kinetics and effects of intravenous nicotine

Abstract

Nicotine was given i.v. to subjects during acid and alkaline urine conditions in doses and a dosing schedule designed to simulate cigarette smoking. Total clearances were greater, terminal half-lifes shorter, but volumes of distribution much the same in acid (pH < 5) and alkaline (pH > 7) urine conditions. The effect of urinary pH on total clearance was due entirely to changes in renal clearance, which accounted for 23% and 2% of total clearance in acid and alkaline urine conditions. Nicotine injections induced a sensation of arousal and increased heart rate and blood pressure over the short term but with repeated injections tolerance to these effects developed rapidly. No differences in subjective or physiologic responses to i.v. nicotine were observed; the effects of smoking a cigarette probably do not differ as a function of urinary pH.