The success of different smoking cessation treatments could be predicted by how quickly smokers break down (metabolise) nicotine in their bodies, according to new research.

The findings come from the largest-ever pharmacogenetic study of tobacco dependence treatment.

They reveal that normal metabolisers of nicotine have better quit rates with a non-nicotine replacement therapy drug (varenicline) compared with the nicotine patch, whereas slow metabolisers achieve similar quitting success using the nicotine patch but without the side-effects reported with the drug.

“As many as 65% of smokers who try to quit relapse within the first week,” explains Caryn Lerman, co-lead author of the report, which was published in the Lancet Respiratory Medicine Journal.

Lerman said its findings show that “matching a treatment based on the rate at which smokers metabolise nicotine could be a viable clinical strategy to help individual smokers choose the cessation method that will work best for them”.