Transdermal clonidine for smoking cessation: A double-blind randomized dose-response study

A 4-week trial tested the effects of 4 doses (placebo, 0.1 mg/d, 0.2 mg/d, and 0.3 mg/d) of transdermal clonidine on smoking cessation and nicotine withdrawal. After a 1-week baseline, smokers (N = 72) started the drug and tried to quit by Week 3. Significantly fewer smokers who received a placebo were abstinent at 5 days after quitting as compared with smokers who received clonidine at any dose (19% vs. 57%, respectively, p = .007). Blood clonidine concentration interacted with nicotine dependence (p < .05): High-dependence smokers who achieved higher blood clonidine concentrations survived longer before smoking a cigarette after quitting, as compared with high-dependence smokers who achieved lower blood levels. Changes from baseline in heart rate, blood pressure, appetite, irritability, and anxiety were inversely associated with blood clonidine concentrations.