A plant extract commonly used in eastern Europe to help smokers kick the habit, appears to work much better than nicotine replacement patches and gums, scientists say.
Cytisine is an alkaloid extract from the laburnum or golden rain tree (Laburnum anagyroides), which grows all over Europe. It works by blocking nicotine's access to the brain's pleasure receptors.
Like nicotine, cytisine is toxic when ingested in large amounts but is safe at low doses. It is produced commercially mainly in Bulgaria and Poland, and has been used as a quitting aid in eastern European countries since the 1960s.
Researchers in New Zealand have conducted a fresh trial of cytisine. They recruited 1,310 smokers who intended to quit and gave exactly half of them cytisine as a course of tablets, taken daily in diminishing doses for 25 days.
The other half received standard nicotine replacement therapy (NRT) - either as patches, gums or lozenges - for two months, 'New Scientist' reported.
The researchers noted the number of people who managed to abstain from smoking at one week, one month, two months and six months into the trial.
Throughout, they found that people taking cytisine were less likely to have smoked than those using NRT. After six months, 143 of the 655 cytisine recipients were still not smoking compared with 100 in the NRT group.
People who received cytisine were slightly more likely to experience side effects, including nausea, vomiting and sleep disturbance, but these were never serious, according to study leader Natalie Walker of the University of Auckland's National Institute for Health Innovation.
Walker said cytisine is more affordable than other quitting aids.
For example, it costs just USD 20 to USD 30 for a 25-day course of treatment, versus USD 100 to USD 700 for a two-month course of NRT depending on the product and who supplies it, or around USD 500 for a three-month course of varenicline (Champix), a drug that works in a similar way to cytisine.
Cytisine is sold as Tabex by Sopharma, a company based in Bulgaria, and as Desmoxan by Aflofarm Pharma of Poland.