• Tobacco and the lung

Cytisine is a partial nicotinic agonist found in high concentrations of laburnum, a plant that grows easily in many parts of the world. This makes it inexpensive to manufacture. The drug has been used for many years in eastern Europe as a smoking cessation aid. The drug came to prominence in the Western world following the development of varenicline, a manufactured nicotinic partial agonist, and the publication of a systematic review of cytisine by Etter in 2006.1 Etter's review and meta-analysis included several trials published in non-English language journals, most of which were not indexed in Pubmed. The review showed evidence of effectiveness, but the trials had methodological weaknesses that detracted from the evidence. In their article published online, Hajek and colleagues2 have updated this review. What has changed?

Since the Etter review, two more studies have been added to the meta-analysis. One of these is a large trial that, had it been done by a pharmaceutical company, might be said to be a typical phase III registration trial.3 The data are now stronger that cytisine is effective. Hajek …