Electronic cigarette user plasma nicotine concentration, puff topography, heart rate, and subjective effects: Influence of liquid nicotine concentration and user experience.

Introduction:
This text presents a study examining the influence of electronic cigarette (ECIG) liquid nicotine concentration and user experience on nicotine delivery, heart rate, puff topography, and subjective effects. The study aims to evaluate the ECIG systematically by holding constant several important device features and liquid constituents while manipulating liquid nicotine concentration and user experience.

Key Points:

* The study included 64 participants, divided into two groups: ECIG-experienced individuals and ECIG-naive cigarette smokers.
* The study found that plasma nicotine data were influenced by abstinence status, and after controlling for this effect, significant three-way condition by time by group interaction was observed.
* Heart rate increased significantly from baseline immediately after bout 1 and 2 in all active liquid nicotine concentrations for both groups.
* Puff topography results showed that ECIG-experienced individuals took significantly longer and larger puffs than ECIG-naive smokers.
* Subjective measures revealed significant condition by group interactions, with ECIG-naive smokers reporting higher scores for "Nausea," "Nervous," "Salivate," and "Sweaty."
* The Direct Effects of Nicotine questionnaire showed a significant condition by group interaction for the item "Sweaty."
* The Direct Effects of ECIG use questionnaire revealed significant condition by group interactions for "Awake," "Pleasant," and "Satisfy."

Main Message:
The study suggests that ECIG-associated nicotine delivery depends on liquid nicotine concentration and user experience. The findings have important regulatory implications, indicating that effective regulation of ECIGs will require systematic evaluation of these products and the effects they produce, including their ability to deliver nicotine to the user. The results also highlight the need for regulation to consider factors beyond liquid nicotine concentration, such as user behavior and device power, to limit ECIG nicotine delivery to the user and prevent potential increases in ECIG abuse and dependence.

Hiler, Marzena, Alison Breland, Tory Spindle, Sarah Maloney, Thokozeni Lipato, Nareg Karaoghlanian, Alan Shihadeh, Alexa Lopez, Carolina Ramôa, and Thomas Eissenberg. “Electronic Cigarette User Plasma Nicotine Concentration, Puff Topography, Heart Rate, and Subjective Effects: Influence of Liquid Nicotine Concentration and User Experience.” Experimental and Clinical Psychopharmacology 25, no. 5 (October 2017): 380–92. https://doi.org/10.1037/pha0000140.