Using varenicline in combination with electronic nicotine delivery systems (ENDS).

Background: Varenicline is efficacious for smoking cessation, but a return to smokingusually occurs after treatment ends. Electronic nicotine delivery systems (ENDS) may enhance smoking reduction and cessation by providing a behavioral substitute for smoking and may deter smoking in the long term if an individual's nicotine dependence can be transferred to ENDS. The goal of this study was to evaluate varenicline in conjunction with ENDS to promote switching to ENDS.

Methods: Twenty-five individuals who smoked cigarettes, interested in switching but not seeking cessation treatment, received ENDS for 13 weeks; during weeks 2-13 they received varenicline. Assessments included self-reported cigarette and ENDS use, expired air carbon monoxide (CO), reward ratings, tolerability/side effects, and dependence measures.

Results: Cigarette smoking decreased from 15.6 cigarettes/day (SD=5.6) at baseline to 2.8 cigarettes/day (SD=5.1) at week 13 (paired t(22)=10.24, p<0.0001). 28% of participants were confirmed to be abstinent in the last 4 weeks of treatment. ENDS use remained relatively constant, averaging 11.8 occasions per day (SD=10.6). Cigarette dependence (assessed by time to first use of the day) decreased after introduction of ENDS (paired t(23) = -3.27, p=0.003), and again after the first week of full-dose varenicline (paired t(23) = -4.27, p=0.0003). Dependence on ENDS did not change, starting out lower than cigarettes (paired t(21) = 5.52, p<0.0001), but ending higher (paired t(22) = 2.94, p=0.008). Smoking satisfaction declined markedly, while satisfaction for ENDS remained relatively constant. Treatment tolerability and adherence were high.

Conclusions: ENDS in combination with varenicline shows promise as a means to reduce dependence on cigarettes and facilitate switching from cigarettes to ENDS.