The effects of extended pre-quit varenicline treatment on smoking behavior and short-term abstinence: a randomized clinical trial

Abstract

Preclinical research and learning theory suggest that a longer duration of varenicline treatment prior to the target quit date (TQD) would reduce smoking rates before cessation and improve abstinence outcomes. A double-blind randomized controlled trial tested this hypothesis in 60 smokers randomized to either an Extended run-in group (4 weeks of pre-TQD varenicline) or a Standard run-in group (3 weeks of placebo, 1 week of pre-TQD varenicline); all the participants received 11 weeks of post-TQD varenicline and brief counseling. During the pre-quit run-in, the reduction in smoking rates was greater in the Extended run-in group than in the Standard run-in group (42% vs. 24%, P < 0.01), and this effect was greater in women than in men (57% vs. 26%, P = 0.001). The rate of continuous abstinence during the final 4 weeks of treatment was higher among women in the Extended group compared to women in the Standard run-in group (67% vs. 35%). Although these data suggest that extension of varenicline treatment reduces smoking during the pre-quit period and may further enhance cessation rates, confirmatory evidence is needed from phase III clinical trials.

Figure 1

Disposition of participants

Figure 2

(a) Unadjusted mean and standard error (SE) cigarettes per day for all Run-in Group × Sex conditions during the five-week pre-quit period. Note. Shaded region reflects the 3-week drug manipulation phase. Baseline (week 1) was used as a covariate in repeated measures ANOVA. (b) Mean (SE) percent reduction in CPD during the pre-quit phase (Final Week Pre-TQD; Week 5 vs. Baseline Week; Week 1) in all Run-in Group × Sex conditions, (c) Mean (SE) expired-air CO measurements for all Run-in Group × Sex conditions during the five-week pre-quit period. Analyses included Baseline (end of week 1) and Drug Manipulation Phase (end of weeks 2 and 4). During the 3-week Drug Manipulation Phase, the Extended Run-in Group received varenicline, while the Standard Run-in Group received placebo, (d) Mean (SE) percent reduction in CO during the pre-quit phase (end of week 4 vs. end of week 1) in all Run-in Group × Sex conditions.

Figure 3

Unadjusted means (SE) for single CEQ item “Did it taste good?” (panel a) and CEQ rush scale (panel b) in reference to the first cigarette of the day by Run-in Group during the five-week pre-quit period. Note. Shaded region reflects the 3-week drug manipulation phase. Baseline (week 1) was used as a covariate in repeated measures ANOVA.

Figure 4

CO-verified 4-week continuous abstinence (not even a puff during the final four weeks of treatment; post-quit weeks 8 through 11) for all Run-in Group × Sex conditions. Note. * p = 0.05.