The efficacy and safety of varenicline for smoking cessation using a flexible dosing strategy in adult smokers: a randomized controlled trial.

ABSTRACTObjective: To determine whether self-regulated flexible dosing with varenicline tartrate is safe and effective for smoking cessation.Research design and methods: 320 healthy, motivated-to-quit smokers (≥10 cigarettes/day) aged 18–65 years, entered a multicenter, randomized, double-blind, placebo-controlled study – conducted between December 26, 2001 and June 24, 2003 – with a 12-week treatment phase and 40-week, double-blind, non-treatment follow-up. Treatment consisted of varenicline or placebo in fixed doses (Week 1: titrated from 0.5 to 1.0 mg/day) followed by a self-regulated flexible schedule (Weeks 2–12: 0.5–2.0 mg/day).Main outcome measures: Primary outcomes included carbon monoxide-confirmed continuous abstinence rate (CAR) from smoking for Weeks 4 through 7, 9 through 12, and 9 through 52. Secondary outcomes included CAR from Weeks 9 through 24, 7-day point prevalence of abstinence, safety assessments, and measures of craving, withdrawal, and smoking reward.Results: Superior CARs were obs...