Old anti-smoking drug passes new test

Cytisine, an extract from the seeds of the Golden Rain acacia that was first marketed in Bulgaria in 1964, can give smokers an inexpensive assist in kicking the habit, according to the first large modern study of the drug.

In the test on 740 volunteers, published in the New England Journal of Medicine, 8.4 percent of those who were given cytisine for 25 days stayed off cigarettes for one year, compared with 2.4 percent in the placebo group. (here)

That success rate is comparable to treatment with nicotine patches and other anti-smoking drugs like varenicline (Chantix) and bupropion (Zyban), chief author Robert West of the University College London told Reuters Health.

Chantix is sold by Pfizer Inc and Zyban is a GlaxoSmithKline product.

It also costs much less - a month of cytisine pills, sold in Central and Eastern Europe under the brand name Tabex, costs about $15 in Poland and $6 in Russia. Nicotine patches and pills to stop smoking typically sell for more than $100 per treatment, depending on the country.

"This is off-patent. In theory, anyone can grow this stuff. The pills can be made for practically nothing," West said.

The drug is not approved in the United States, Japan or Western Europe.

Cytisine for smoking cessation: a literature review and a meta-analysis. Cytisine is an agonist of nicotinic receptors; in particular, it binds strongly with alpha(4)beta(2) nicotinic receptors. Cytisine has been used to treat tobacco dependence for 40 years in Eastern Europe.

RESULTS: Ten studies reported the effects of cytisine on smoking cessation, including 4 controlled studies (3 placebo controlled). Nine studies used the Bulgarian drug Tabex, containing 1.5 mg of cytisine per tablet, and one Russian study used buccal films containing either 1.5 mg of cytisine or 0.75 mg of cytisine plus 0.75 mg of anabasine. All studies were published between 1967 and 2005 in Bulgaria, Germany, Poland, and Russia. There were 4404 smokers treated with cytisine and 3518 in control conditions. The pooled odds ratio after 3 to 8 weeks in the 3 placebo-controlled trials (2 were double blind and 1 was randomized) was 1.93 (95% confidence interval, 1.21-3.06). For the 2 placebo-controlled double-blind trials with a longer follow-up, the pooled odds ratio after 3 to 6 months was 1.83 (95% confidence interval, 1.12-2.99). One placebo-controlled double-blind trial had follow-up after 2 years (odds ratio, 1.77; 95% confidence interval, 1.29-2.43). Some adverse effects were reported. Most trials were, however, of poor quality.

###

Etter JF.

Institute of Social and Preventive Medicine, University of Geneva, 1 rue Michel-Servet, CH-1211 Geneva 4, Switzerland. jean-francois.etter@imsp.unige.ch

Smoking kills an estimated five million people worldwide each year, and 95 percent of people who try to quit without help fail to stay off tobacco for six months or longer. Most can't afford some of the drugs found to be effective in improving the quit rate.