Pharmacokinetics of nicotine in rats after single-cigarette smoke inhalation.

The amount of nicotine absorbed following cigarette smoke inhalation was evaluated by comparing the area under the plasma concentration--time curve and urinary recovery with those observed after its intravenous injection to rats. Nicotine was adsorbed rapidly, with the maximum plasma concentration occurring immediately after cessation of cigarette smoke exposure. On the average, 68% of the nicotine delivered to the inhalation chamber was absorbed. The absorption and elimination of nicotine, as well as the formation and elimination of its metabolites, followed first-order kinetics, and the derived pharmacokinetic parameters were similar to those observed after the intravenous administration of nicotine.