Effects of increasing urinary pH on cigarette smoking.

We evaluated the effects of increasing urinary pH on sensitive automated measures of cigarette smoking behavior. Urine was alkalized by oral doses of 50 or 75 mg/kg sodium bicarbonate. Measurements of cigarette smoking behavior included the number of cigarettes smoked and automated measures of puff frequency and duration. The sodium bicarbonate resulted in little or no change in the number of cigarettes smoked, but in five of the seven subjects frequency and duration of cigarette puffs after sodium bicarbonate decreased 10% to 15%. The small decreases in cigarette smoking brought about by sodium bicarbonate cannot be expected to have significant overall effects.