Rates of continuous abstinence in the last 3 weeks were greater for the medication groups than the placebo group : 30.2 % for the 80-mg group ( OR = 11.87 ; 95 % CI , 2.25-62 .62 ; P = .004 ) and 17.5 % for the 60-mg group ( OR = 5.85 ; 95 % CI , 1.04-33 .04 ; P = .04 ) vs 7.0 % for placebo .