The effect of smoking on nicotine metabolismin vivoin man

Abstract Nicotine and a basic metabolite, cotinine, were determined in the urine by gas-liquid chromatography after intravenous administration of (—)-nicotine hydrogen (+)-tartrate to groups of male and female smokers and non-smokers in whom the urine was maintained at an acid pH. The urinary recoveries of nicotine and cotinine from male smokers fell in two groups. One showed a lower recovery of both alkaloids than was seen with male non-smokers. The other showed a similar recovery of nicotine but more cotinine than the male non-smokers. Female smokers excreted less nicotine but more cotinine than female non-smokers. More nicotine but less cotinine was excreted by female non-smokers than by male non-smokers. The results show sex dependent metabolism of nicotine occurs in non-smoking humans and that smoking causes alterations in nicotine metabolism.