Researchers say that blood tests for cotinine, a common nicotine metabolite, can be used to determine the potential effectiveness of stop-smoking patches.

The urine or saliva test measures the rate at which individuals metabolize nicotine, providing clues about the intensity of craving and a predictor of their likelihood of success in quitting. "The ultimate aim here is to distinguish smokers who are likely to benefit from a standard dose of nicotine patch from those who may need a higher dose patch or an alternative therapy in order to succeed in quitting," said lead researcher Caryn Lerman, Ph.D., director of the University of Pennsylvania Transdisciplinary Tobacco Use Research Center.

The study included an experiment that used the blood tests as an adjunct to stop-smoking treatment using nicotine patches or nasal sprays. "Using the rate of nicotine metabolism, we were able to predict the level of cravings and the efficacy of the nicotine patch," said Lerman. "Similar results could not be obtained for the nicotine spray, most likely because the subjects were able to compensate for rapid metabolism of nicotine by using the spray more often."

The research was published in the June 2006 issue of the Journal of Clinical Pharmacology and Therapeutics.