A Pilot Study of E-Cigarette Naïve Cigarette Smokers and the Effects on Craving After Acute Exposure to E-Cigarettes in the Laboratory.

BACKGROUND AND OBJECTIVES: Recent surveys confirm continued increases in the use of electronic-cigarettes (e-cigarettes) in adolescents and adults. Users often state that e-cigarettes reduce tobacco craving and withdrawal symptoms in addition to their smoking. Data from laboratory studies and clinical trials have confirmed these statements, though there are inconsistencies in the outcomes. In this pilot study, we set out to evaluate the effects of e-cigarettes, as compared to the participants' own cigarettes, on baseline craving and smoking severity. METHODS: Using a within-subjects, placebo-controlled study design, 15 tobacco-dependent, e-cigarette naïve participants sustained abstinence overnight. They completed distinct phases of this protocol during four separate study sessions. Participants were randomized to an e-cigarette device containing one of three doses of nicotine (0, 18, or 36 mg/ml) or their own cigarette. Each study visit was ~3 hours long and separated by at least 7 days. Visits included assessments of craving and smoking severity. RESULTS: The data showed that after 10 puffs in both the Own cigarette and e-cigarette conditions, breath carbon monoxide levels increased significantly in the former but not the latter. Questionnaire of Smoking Urges and Choices to Smoke scores were not statistically different across groups after two distinct bouts of 10 puffs each. Additionally, E-cigarette Perceptions Questionnaire responses were not significantly different according to dose. CONCLUSION AND SCIENTIFIC SIGNIFICANCE: This experiment provides data demonstrating that e-cigarettes did not reduce craving or smoking severity in e-cigarette naïve users. However, since this was a pilot study, the conclusions that can be drawn are limited. (Am J Addict 2019;28:361-366).

Guanfacine Attenuates Adverse Effects of Dronabinol (THC) on Working Memory in Adolescent-Onset Heavy Cannabis Users: A Pilot Study.

The cannabinoid-1 receptor (CB1R) agonist Δ9-tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis, adversely effects working memory performance in humans. The α2A-adrenoceptor (AR) agonist guanfacine improves working memory performance in humans. The authors aimed to determine the effects of short-term (6 days) treatment with guanfacine on adverse cognitive effects produced by THC. Employing a double-blind, placebo-controlled crossover design, the cognitive, subjective, and cardiovascular effects produced by oral THC (20 mg) administration were determined twice in the same cannabis users: once after treatment with placebo and once after treatment with guanfacine (3 mg/day). Compared with performance at baseline, THC negatively affected accuracy on spatial working memory trials while participants were maintained on placebo (p=0.012) but not guanfacine (p=0.497); compared with placebo, accuracy was significantly (p=0.003, Cohen's d=-0.640) improved while individuals were treated with guanfacine. Similarly, compared with baseline, THC increased omission errors on an attentional task while participants were maintained on placebo (p=0.017) but not on guanfacine (p=0.709); compared with placebo, there were significantly (p=0.034, Cohen's d=0.838) fewer omissions while individuals were maintained on guanfacine. Although THC increased visual analog scores of subjective effects and heart rate, these increases were similar during treatment with placebo and guanfacine. THC did not significantly affect performance of a recognition memory task or blood pressure while individuals were maintained on either treatment. Although preliminary, these results suggest that guanfacine warrants further testing as a potential treatment for cannabis-induced cognitive deficits.