The recent approval of cytisine in the UK marks a significant milestone in the management of tobacco dependency. As healthcare professionals, it is crucial to understand the efficacy, mechanism of action, advantages, availability, prescription guidelines, and potential side effects of this medication to optimize its use in clinical practice.
Cytisine, a partial agonist and antagonist of nicotinic acetylcholine receptors, has demonstrated clinical effectiveness in randomized controlled trials.1,2,3,4 Indeed, a placebo-controlled trial of cytisine for smoking cessation showed the sustained 12-month abstinence rate was 8.4% in the cytisine group compared to 2.4% in the placebo group (95% confidence interval [CI], 2.7 to 9.2; P=0.001).1 Additionally, a 2023 Cochrane systematic review confirmed cytisine as an effective treatment for achieving abstinence from tobacco and indicated that it was one of the most effective treatments for tobacco dependency alongside varenicline and electronic nicotine delivery systems.5,6 Moreover, cytisine offers cost-savings as economic models estimate that cytisine treatment would produce lower mean lifetime costs, driven by its effectiveness compared to other tobacco dependency treatments.7
Cytisine’s dual partial agonist and antagonist properties work by binding to nicotinic acetylcholine receptors in the brain and mimicking the effect of nicotine (agonist), thereby antagonizing the effects of nicotine, reducing the potent dopamine surges with nicotine use and the cycle of cravings and withdrawal symptoms associated with nicotine dependence.8 As a partial agonist, cytisine provides a milder stimulation compared to nicotine, helping individuals gradually taper off their dependence on cigarettes.
One of the notable advantages of cytisine is its cost-effectiveness compared to other tobacco dependency therapies. Cytisine also leads to fewer adverse events than other nicotine analogs such as varenicline.4 Cytisine therefore offers a cheaper and better-tolerated treatment without unduly compromising efficacy. Additionally, its short course of treatment (25 days), oral administration, and relatively simple dosing regimen enhance patient compliance and convenience.
Cytisine has been available for smoking cessation in several countries, including Eastern Europe and Russia, for decades. Its recent approval in the UK expands access to this medication in Western markets, providing healthcare professionals with another tool to combat tobacco dependency. Efforts are under way to make cytisine more widely accessible across other regions, acknowledging its potential to address the global burden of smoking-related illnesses.
Healthcare professionals should prescribe cytisine according to recommended dosing schedules and guidelines. Typically, the treatment involves a 100-tablet course of cytisine (1.5mg per tablet) for 25 days, beginning with 6 tablets a day and ending at 2 tablets a day, though dosage adjustments based on individual response and tolerability are possible. Counseling and behavioral support should complement pharmacotherapy to maximize abstinence outcomes.9
While cytisine is generally well-tolerated, it may cause side effects such as nausea, vomiting, and gastrointestinal disturbances, all common symptoms when the nicotinic receptors are saturated by agonists (cytisine or varenicline). Contraindications include pregnancy, breastfeeding, recent myocardial infarction, recent cerebrovascular event, and significant cardiac arrhythmia. Caution is advised for those over age 65 or patients with renal or liver impairment. As with all tobacco dependency treatments, any risks should be weighed against the substantial harms of smoking.
In summary, cytisine more than doubles the chance of cessation with no known safety concerns.10 The recent approval of cytisine in the UK heralds a new era in the management of tobacco dependency. Its efficacy, affordability, and relatively favorable side effect profile position it as a valuable addition to existing tobacco dependency interventions. However, healthcare professionals must remain vigilant regarding its prescription, monitor for adverse effects, and provide comprehensive support to individuals embarking on the journey toward tobacco abstinence. By harnessing the potential of cytisine, we can make meaningful strides in reducing the global burden of smoking-related diseases and improving public health outcomes.
References
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- 9. United States Preventive Services Task Force. Tobacco Smoking Cessation in Adults, Including Pregnant Persons: Interventions 2021 [Available from: https://www.uspreventiveservicestaskforce.org/uspstf/recommendation/tobacco-use-in-adults-and-pregnant-women-counseling-and-interventions.
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