Effect of clonidine on cigarette cessation and in the alleviation of withdrawal symptoms.

One hundred and eighteen cigarette smokers who wished to give up were randomly assigned to receive either clonidine (n=42), diazepam (n—38) or placebo (n=38) in a double-blind trial. All subjects also received at least three sessions of behavioural treatment. End of treatment abstinence rates for clonidine, diazepam and placebo groups were 69%, 40% and 40% respectively (p<0.01). At later follow-up, averaging 4.5 months from the end of treatment, abstinence rates were 57%, 37% and 37% respectively (NS). Compared with diazepam and placebo, clonidine received more positive ratings (p<0.005) and was more effective in relieving withdrawal symptoms (p<0.05). This report demonstrates that clonidine helps smokers to quit. The mechanism of action may involve decreased firing of a-2-noradrenergic cells in the locus coeruleus.