Dexamethasone attenuation of the cortisol response to nicotine in smokers.

The effect of corticosteroids upon the cortisol response to nicotine from smoking was investigated in five heavy smokers. Corticosteroid activity was manipulated by administering dexamethasone, a synthetic glucocorticoid (1 mg orally, 14 h before), in a double-blind, placebo-controlled procedure. Testing took place in the middle of the day and involved the smoking of two high-nicotine (2.87 mg) research cigarettes over a 15-min period. The dexamethasone condition was characterized by a pronounced suppression of baseline plasma cortisol, as expected, and by a significant dampening of the cortisol response to nicotine, indicating diminished sensitivity to nicotine under conditions of enhanced corticosteroid activity.