Endocrine effects of nicotine administration, tobacco and other drug withdrawal in humans.

The focus of this manuscript is on the effects of smoking and tobacco withdrawal on the hypothalamic-pituitary axis (HPA). A variety of studies have shown that nicotine administered intravenously or through intense cigarette smoking can induce changes in hormones associated with the HPA. Administration of, and abrupt cessation from, other drugs of abuse has also been shown to affect levels of these hormones. Additionally, many of the symptoms of stress and tobacco withdrawal overlap suggesting that the hormonal changes seen during periods of stress may be observed during tobacco abstinence. These findings led to a study of the effects of tobacco withdrawal on plasma ACTH, cortisol, and prolactin levels. The results indicated tobacco cessation caused small and transient effects on plasma hormone levels which were not significantly influenced by nicotine replacement and were not related to other signs of withdrawal.