Table 1

Summary of controlled trials of cytisine for smoking cessation

First authorStudy design and quality*Study populationBehavioural supportLength of follow-upMain resultsConfounders/ comments
Paun (1968)Placebo-controlled trial (−)Cytisine: N=366
Placebo: N=239
Unclear8 weeksCytisine: 55% (n=202)
Placebo: 33% (n=80)
No validation of abstinence
Non-randomised, results of 2 sites using drug compared with 3rd site using placebo
Scharfenberg (1971), Benndorf (1968), Benndorf 1968Randomised placebo-controlled trial (+)Exclusions: hypertension, arteriosclerosis
Cytisine: N=607
Placebo: N=607
Initial session and follow-up 4–6 weeks after starting treatment4 weeks
6 months
2 years
Cytisine: 65% (n=395)
Placebo: 41% (n=246)
Cytisine: 30% (n=185)
Placebo: 16% (n=97)
Cytisine: 21% (n=127)
Placebo: 13% (n=79)
No validation of abstinence
Two-year follow-up by mail with 66% response rate
Schmidt (1974)Randomised placebo-controlled trial (+)N=2470 smokers recruited via TV and newspaper ads
Cytisine: N=250
Placebo: N=270
Single information lecture4 weeks
3 months
Cytisine: 41% (n=103)
Placebo: 31% (n=84)
Cytisine: 25% (n=68)
Placebo: 21% (n=57)
No validation of abstinence
All contacts by post, 74% response rate at 3 months
Marakulin (1984)Controlled trial (−)Autogenic training (AT): N=232
Autogenic training + cytisine: N=388
Inpatient autogenic training treatment3 weeksAT alone: 53% (n=123)
AT+cystisine: 70.1% (n=272)
No validation of abstinence
Unclear allocation to groups
No placebo
Monova (2004)Randomised placebo-controlled trial (−)Cytisine: N=75
Placebo: N=75
8 visits over 60 days to review smoking diary and for laboratory tests26 daysCytisine: 37% (n=28)
Placebo: 3% (n=2)
Unclear whether double blind
Collected urinary cotinine but unclear if used
Vinnikov (2008)Randomised placebo-controlled trial (++)Exclusions: Serious or unstable medical conditions
Cytisine: N=85
Placebo: N=86
‘2 weeks screening and counselling’ followed by medication use8 weeks
6 months
Cytisine: 10.6% (n=9)
Placebo: 5.8% (n=5)
Cytisine: 10.6% (n=9)
Placebo: 1.2% (n=1)
Russell Standard outcome CO validated
West (2011)Randomised placebo-controlled trial (++)Exclusions: Current psychiatric disorder
Cytisine: N=370
Placebo: N=370
Baseline visit, telephone calls on quit date and 1 week, a visit at 4 weeks6 month
12 months
Cytisine: 10.0% (n=37)
Placebo: 3.5% (n=13)
Cytisine: 8.4% (n=31)
Placebo: 2.4% (n=9)
Russell Standard outcome CO validated
  • *Quality ratings take into account study design and features highlighted in the column confounders/comments.