Coffee drinking enhances the analgesic effect of cigarette smoking.

Nicotine (from cigarette smoke) and caffeine (from coffee) have analgesic effects in humans and experimental animals. We investigated the combined effects of coffee drinking and cigarette smoking on pain experience in a group of moderate nicotine-dependent, coffee drinking, young smokers. Pain threshold and pain tolerance were measured during cold pressor test following the habitual nocturnal deprivation of smoking and coffee drinking. Smoking increased pain threshold and pain tolerance in both men and women. Coffee drinking, at a dose that had no independent effect, doubled the increase in pain threshold induced by smoking. The effect could not be explained by a cumulative raise in blood pressure. Our data suggest that caffeine enhances the analgesic effect of nicotine.