Rapid Brain Nicotine Uptake from Electronic Cigarettes.

This study sought to determine brain nicotine kinetics from use of the increasingly popular electronic cigarette (E-cig). In 17 E-cig users (9 men and 8 women), brain uptake of nicotine after inhalation from E-cigs was directly assessed using C-nicotine PET. The brain nicotine kinetics were compared with those from smoking combustible cigarettes (C-cigs). A single puff of E-cig vapor caused the nicotine concentration in the brain to rise quickly (mean time to reach 50% of maximum brain nicotine concentration, 27 s), with a peak amplitude 25% higher in women than men, resembling previous observations with C-cigs. Nonetheless, the accumulation from E-cigs (24%) was less than that from C-cigs (32%) in both men and women. E-cigs can deliver nicotine to the brain with a rapidity similar to that of C-cigs. Therefore, to the extent that rapid brain uptake promotes smoking reward, E-cigs might maintain a degree of nicotine dependence and also serve as a noncombustible substitute for cigarettes.