Clonidine for smoking cessation.
BACKGROUND
Clonidine was originally used to lower blood pressure. It acts on the central nervous system and may reduce withdrawal symptoms in various addictive behaviours, including tobacco use.


OBJECTIVE
The aim of this review is to determine clonidine's effectiveness in helping smokers to quit.


METHODS
We searched the Cochrane Tobacco Addiction Group trials register for trials of clonidine. Date of the most recent search: May 2004.


METHODS
We considered randomized trials of clonidine versus placebo with a smoking cessation endpoint assessed at least 12 weeks following the end of treatment.


METHODS
We extracted data in duplicate on the type of subjects, the dose and duration of clonidine therapy, the outcome measures, method of randomization, and completeness of follow up. The main outcome measure was abstinence from smoking after at least 12 weeks follow up in patients smoking at baseline. We used the most rigorous definition of abstinence for each trial, and biochemically validated rates if available. Where appropriate, we performed meta-analysis using a fixed effect model.


RESULTS
Six trials met the inclusion criteria. There were three trials of oral, and three of transdermal clonidine. Some form of behavioural counselling was offered to all participants in five of the six trials. There was a statistically significant effect of clonidine in one of these trials. The pooled odds ratio for success with clonidine versus placebo was 1.89 (95% confidence interval 1.30 to 2.74). There was a high incidence of dose-dependent side-effects, particularly dry mouth and sedation.


CONCLUSIONS
Based on a small number of trials, in which there are potential sources of bias, clonidine is effective in promoting smoking cessation. Prominent side-effects limit the usefulness of clonidine for smoking cessation.
Gourlay
S G
SG
16 Manning Street, Queens Park, Australia, NSW 2022. gourlaysf@yahoo.com
Stead
L F
LF
Benowitz
N L
NL
D003000:Clonidine / Q000627:therapeutic use*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D016540:Smoking Cessation; D000074606:Smoking Prevention
D003000:Clonidine