Smoking cessation success is dependent on how quickly smokers break down nicotine in their body, a study has found.

The use of smoking cessation aid such as varenicline was effective amongst those who metabolise nicotine in quitting compared to when they used a nicotine patch.

For those that metabolise nicotine slowly, similar success in quitting was found through the use of nicotine patches with many people complaining about the side effects of varenicline.

It is claimed as many as 65% of smokers who try to quit will relapse in the first week.

Around six million people a year die due to smoking related diseases with more than £130bn spent annually on tobacco related health costs across the world.  

More than 1200 smokers were involved in a trial lasting 11 weeks involving a nicotine patch, varenicline and a placebo pill and patch. They also received behavioural counselling and were monitored for 12 months after they quit.

At the end of the trial, normal metabolisers of nicotine taking varenicline were twice as likely to not smoke as those using nicotine patches and were significantly more likely to be abstaining six months later. 

Co-lead author, Dr Rachel Tyndale, said: “It is feasible that a point-of-care blood test to measure the rate at which nicotine is metabolised could be developed and implemented in clinical practice.”