Opioid-induced biochemical alterations of the neuroendocrine axis

Exogenous opioids have been used for decades to palliate cancer-related pain and other cancer-related manifestations and, more recently, to treat patients with pain not related to oncologic disease. While the goal of opioid treatment is symptomatic relief and improved quality of life, these patients often suffer from adverse side effects, including endocrine system abnormalities, of which hypogonadism is the best known. Opioids may interact with other hypothalamic-pituitary pathways and endocrine end organs, and in most cases these interactions are subtle and the effects unclear. The long-term effects of these agents on the endocrine system are still largely unknown. This article discusses the various effects of opioid agents on the endocrine system and provides information that allows early recognition of side effects that may alter the quality of life of patients affected by pain, awareness of the potential complications in opioid addicts, and detection and treatment of side effects in participants of an opioid detoxification program.