Active pharmacotherapy decreased the rate of relapse across all participants by almost half in comparison to placebo, adjusted for age, gender, and metabolism based on CYP2A6 genotype (HR=0.51, 95%CI=0.38-0.68, p=4.3x10-6). However, the association of metabolism and relapse was significantly moderated by medication status (placebo vs. active pharmacotherapy) (interaction effect size=2.81, 95%CI=1.32-5.99, p=0.0075; Table 1A). Pharmacotherapy was highly effective in fast metabolizers (HR=0.39, 95%CI=0.28-0.55, p=1.97x10-8) but not in slow metabolizers (HR=1.09, 95%CI=0.55-2.17, p=0.80). Figure 1 illustrates the effect of pharmacotherapy on relapse in fast and slow metabolizers.
