OBJECTIVES: Cytisine (Tabex) has been licensed in Eastern Europe as an aid to 
smoking cessation for 40 years. Cytisine is a partial agonist with high affinity 
binding to the alpha4beta2 nicotinic acetylcholine receptor believed to be 
central to the rewarding effect of nicotine. There is insufficient information 
on effectiveness to warrant licensing by modern standards. To assess whether 
full-scale controlled trials are warranted, this study sought to obtain an 
estimate of the 12-month continuous abstinence rates of smokers using cytisine 
with minimal behavioural support.
DESIGN: An uncontrolled, open-label trial.
SETTING: A smokers' clinic in an oncology centre in Warsaw, Poland.
SUBJECTS: 436 consecutive attendees of the smokers' clinic of whom 191 were 
male. The mean dependence score (Fagerstrom Test for Nicotine Dependence) was 
6.1.
INTERVENTION: The standard regimen of Tabex (cytisine) was used, involving 25 
days of treatment with minimal behavioural support.
MAIN OUTCOME MEASURE: Self-reported continuous abstinence for 12 months; with 
abstinence verified by carbon monoxide at the final follow up (after 12 months).
RESULTS: 60 participants (13.8% of the total sample) were abstinent for 12 
months. Of the 315 subjects, who had taken the drug, 49 (15.5%) stopped cytisine 
because of adverse effects (mostly gastric disturbances and nausea), although 
they were not serious. The frequency of the minor adverse effects, primarily 
gastric disturbance, was similar to that observed in previous studies with the 
drug.
CONCLUSIONS: The long-term abstinence rates were similar to those observed in 
smokers receiving nicotine replacement therapy. Full-scale randomised trials of 
cytisine (Tabex), conducted to the standards required by regulatory authorities, 
are warranted.