Smoking Cessation: Is cytisine as effective as nicotine-replacement therapy for smoking cessation?

N. Walker and Others

Four systematic reviews report cytisine to be superior to placebo for short-term and long-term smoking abstinence. No trials have compared cytisine with nicotine-replacement therapy; a pragmatic, open-label, noninferiority trial conducted in New Zealand investigated whether cytisine was at least as effective as nicotine-replacement therapy.

  What is cytisine?

Cytisine is a plant-based alkaloid found in members of the Leguminosae family. Like varenicline, cytisine is a partial agonist of nicotinic acetylcholine receptors (nAChRs), with an affinity for the α4β2 receptor subtype, and a half-life of 4.8 hours. Cytisine remains relatively unknown outside Eastern Europe despite calls for licensing worldwide because of its proven benefits, low cost as compared with other cessation medications (cytisine, $20 to $30 for 25 days; nicotine-replacement therapy, $112 to $685 for 8 to 10 weeks; varenicline, $474 to $501 for 12 weeks), and low cost per quality-adjusted-life-year.

  Is cytisine as effective as nicotine-replacement therapy for smoking cessation?

Cytisine was not only noninferior to nicotine-replacement therapy but had superior effectiveness: 1-month continuous abstinence rates were significantly higher in the cytisine group (40%, 264 of 655) than in the nicotine-replacement therapy group (31%, 203 of 655) (risk difference, 9.3 percentage points; 95% confidence interval [CI], 4.2 to 14.5; number needed to treat, 11). The effectiveness of cytisine for continuous abstinence was superior to that of nicotine-replacement therapy at 1 week, 2 months, and 6 months.

Table 2. Continuous Abstinence and 7-Day Point-Prevalence Abstinence According to Treatment Group, According to the Intention-to-Treat Analysis.