The length of time a smoker uses transdermal (patch) nicotine replacement affects their chances of success in quitting, US researchers report. A new study, published in the February 2010 Annals of Internal Medicine, compared extended-duration transdermal nicotine therapy with standard-duration therapy in 568 adult smokers. One group used standard eight-week 21mg/day nicotine patch therapy followed by 16 weeks of placebo (dummy) patches, and the extended therapy group used 24 weeks of the nicotine patch – smokers were not told which group they were in. The researchers from the Department of Psychiatry at the University of Pennsylvania found, "At week 24, extended therapy produced higher rates of point-prevalence abstinence (31.6% vs 20.3%), prolonged abstinence (41.5% vs 26.9%) and continuous abstinence (19.2% vs 12.6%) versus standard therapy.” All participants were tested biochemically to detect whether they had smoked. Extended therapy also reduced the risk for and delayed lapsing back into smoking and increased the chances of recovery from lapses. By week 52, extended therapy produced higher quit rates for prolonged abstinence only. No differences in side effects between the groups were found. It remains to be seen how the commonly used therapy of tapering off of nicotine doses after eight weeks compares to either of the approaches in this study.