Pharmacokinetic disposition of multiple-dose transdermal nicotine in healthy adult smokers.

The pharmacokinetics and cardiovascular effects of nicotine and its major metabolite, cotinine, were characterized during repeated once-daily application for 5 days of a 30-cm2 nicotine transdermal system, Nicotine TTS (Habitrol), to nine healthy, black, adult, male smokers. Subjects abstained from smoking throughout the study. Pharmacokinetic analysis indicated that nicotine was delivered from Nicotine TTS for the 24-hr application period averaging 0.76 mg/cm2/24 hr, and at a relatively constant rate compared to other modes of drug administration. The transdermal clearance of nicotine, 1351 ml/min, coincided with reported values following intravenous nicotine administration; however, the terminal-phase half-life, 5.0 hr, did not. An analysis of the components of variance contributing to the variability in nicotine delivery from repetitive application of Nicotine TTS indicated that the in vivo transdermal permeation of nicotine is rate limited by both the device and the intrinsic skin conductivity. Clinical cardiovascular side effects were negligible as an apparent result of subclinical vasopressive nicotine concentrations, although drug activity with regard to other effects was manifested.