Nicotine delivery, retention and pharmacokinetics from various electronic cigarettes

Introduction:
This article reports a study examining the delivery, retention, and pharmacokinetics of nicotine and other substances from electronic cigarettes (e-cigarettes). The study measures the systemic retention of nicotine, propylene glycol, and vegetable glycerin in e-cigarette users and assesses the abuse liability of e-cigarettes by characterizing nicotine pharmacokinetics.

Key Points:

* The study recruited 13 experienced adult e-cigarette users who took 15 puffs from their usual brand of e-cigarette.
* Exhaled breath was trapped in gas-washing bottles and blood was sampled before and several times after use.
* Plasma nicotine was analyzed by gas chromatography-mass spectrometry (GC-MS/MS) and nicotine, VG, and PG in e-liquids and gas traps were analyzed by LC-MS/MS.
* E-cigarettes delivered an average of 1.33 (0.87-1.79) mg of nicotine, with 93.8% of the inhaled dose retained systemically.
* Average maximum plasma nicotine concentration (Cmax) was 8.4 (5.4-11.5) ng/ml and time of maximal concentration (Tmax) was 2-5 minutes.
* 84.4% and 91.7% of VG and PG, respectively, were systemically retained.
* Heart rate increased by an average of 8.0 beats per minute after 5 minutes.
* Withdrawal and urge to smoke decreased and e-cigarettes were described as satisfying.

Main Message:
The study demonstrates that e-cigarettes can deliver levels of nicotine comparable to or higher than traditional tobacco cigarettes, with similar systemic retention. The pharmacokinetic curve of nicotine absorption from e-cigarettes is similar to that of tobacco cigarettes, suggesting potential addictive properties. The study also highlights the importance of continued monitoring of e-cigarette effectiveness as nicotine delivery devices and potential abuse liability.

St.Helen, Gideon, Christopher Havel, Delia A. Dempsey, Peyton Jacob, and Neal L. Benowitz. “Nicotine Delivery, Retention and Pharmacokinetics from Various Electronic Cigarettes.” Addiction 111, no. 3 (March 2016): 535–44. https://doi.org/10.1111/add.13183.