Rapid Brain Nicotine Uptake from Electronic Cigarettes.

Introduction:

This text presents the results of a study examining brain nicotine kinetics from the use of electronic cigarettes (E-cigs) compared to combustible cigarettes (C-cigs). The study used PET scanning to directly assess brain uptake of nicotine after inhalation from E-cigs and C-cigs in 17 E-cig users and 19 C-cig smokers. The key points from the study are summarized below.

**Key Points:**

* E-cigs delivered nicotine to the brain with a rapidity similar to that of C-cigs.
* The accumulation of nicotine in the brain from E-cigs was less than that from C-cigs in both men and women.
* after inhalation of a single puff of E-cig vapor, the nicotine concentration in the brain rose quickly, similar to that after a puff from C-cigs.
* The lower brain nicotine accumulation after E-cig use than after C-cig use may be due in part to a lower arterial-blood nicotine concentration, which would be due to greater nicotine retention in the upper respiratory tract from vapor than from smoke.
* The observed more intensive brain nicotine accumulation from E-cigs in women than men might reflect sex differences in respiratory tract anatomy or in hemodynamics.
* The slower brain nicotine delivery of E-cigs than of C-cigs can be compensated for by the higher nicotine content of e-liquids or by more intensive vaping to achieve a desired effect.
* The study was supported by the NIh and the american Cancer Society.

**Main Message:**

The study suggests that E-cigs can deliver nicotine to the brain with a rapidity similar to that of C-cigs, which may maintain a degree of nicotine dependence and serve as a noncombustible substitute for cigarettes. however, the lower accumulation of nicotine in the brain from E-cigs compared to C-cigs may reduce their addictive potential. The study also highlights the need for further research to understand the pharmacokinetics of nicotine delivery from E-cigs and the potential impact on smoking cessation. additionally, regulatory measures may be necessary to ensure the safe use of E-cigs and prevent nicotine addiction, especially in vulnerable populations such as women and young people.

Solingapuram Sai KK, Zuo Y, Rose JE, et al. Rapid Brain Nicotine Uptake from Electronic Cigarettes. Journal of nuclear medicine : official publication, Society of Nuclear Medicine. 2020;61(6):928-930. doi:10.2967/jnumed.119.230748