Wearing the patch prior to quitting may help
However, numerous studies have shown that nothing terrible happens when you smoke while wearing the patch. 15 years ago I published a study in which 30 smokers smoked normally for 2 weeks, and wore full strength nicotine patches for one of those weeks and placebo patches for the other. The smokers generally couldn’t tell which week was the week with the nicotine patches and the single participant who vomited did so while wearing placebo patches! So it appears to be very unlikely for smokers to experience adverse events caused by wearing the patch while smoking.
However, some recent studies have actually suggested that wearing the patch for a few weeks prior to the target quit date may actually increase the chances of a successful quit. One such study was carried out by Dr Schuurmans and colleagues in South Africa. They found that people who wore nicotine patches for two weeks prior to their quit day had better long term quit rates than smokers who wore placebo patches for two weeks prior to their quit date (22% vs 12% quit, 6 months later).
Interestingly, studies of the use of other forms of nicotine replacement therapy by smokers not intending to quit have also found that not only does the NRT help them to reduce their cigarette consumption, but that a significant proportion of them go on and quit completely. One such study was carried out by Dr Batra and colleagues in Germany. They recruited over 300 smokers who were interested in cutting down but not quitting. They were provided with either 4mg nicotine gum or placebo gum for a year. As well as helping with smoking reduction, the group receiving the nicotine gum had significantly more people who were quit 13 months later (12% versus 5%).
We are not clear on the mechanism whereby combining NRT with smoking prior to quitting may help subsequent cessation. It may simply be that it loosens the associations between smoking and reinforcement (by providing nicotine separately from smoking). Just to be clear, the use of NRT prior to the quit date is not yet normal practice, and may never become so. My current practice is to advise patients using the patch to put their first patch on the morning of their quit day and not before (as suggested on the box). However, as more evidence is gathered on the safety and effectiveness of NRT pre-treatment, I may have to reconsider.