Abuse liability of cigarettes with very low nicotine content in pregnant cigarette smokers

The U.S. Food and Drug Administration has proposed reducing the nicotine content of cigarettes to a minimally-addictive level. To our knowledge, this study is the first to examine how pregnant smokers respond to very low nicotine content (VLNC) cigarettes. In Phase 1, participants blindly sampled two VLNC cigarettes (0.4 and 2.4 mg/g of tobacco) and their usual brand (UB) cigarette in separate sessions, then completed a behavioral economic simulation task and measures of subjective effects, craving/withdrawal, and smoking topography. Phase 2 directly compared the relative reinforcing effects of the cigarettes using concurrent choice testing. All possible dose-pair combinations were tested in separate sessions where puffs were earned ad libitum by clicking the code associated with their preferred cigarette 10 times. Phase 3 tested the 0.4 mg/g-UB dose-pair where UB puffs could be earned with a progressively incremented number of clicks (maximum 8400). Ten pregnant smokers in Burlington, VT and Baltimore, MD participated in 2017-2018. Regarding abuse liability, participants chose the 0.4-mg/g dose less than UB (22% vs. 78%) during concurrent choice testing and the 0.4-mg/g dose sustained less demand than the 2.4-mg/g and UB doses on the simulation task. Positive subjective effects were also lower for both VLNC cigarettes vs. UB. Each cigarette reduced nicotine craving/withdrawal and no significant changes indicative of compensatory smoking were noted. Reducing the nicotine content of cigarettes may decrease their abuse liability in pregnant smokers without causing untoward craving/withdrawal or compensatory smoking. Studies of extended exposure to VLNCs in pregnant women are warranted.