The effects of opioids on the endocrine system: an overview

Opioids commonly used for pain relief may lead to hypogonadism, which is characterised by suppression of production of the gonadotropin-releasing hormone (GnRH) resulting in inadequate production of sex hormones. The aim of this narrative review was to highlight the effects of opioids on the endocrine system and the development of hypogonadism. MEDLINE, EMBASE and Cochrane Library were searched for relevant articles investigating hypogonadism in patients undertaking opioid therapy by using a combination of both indexing and free-text terms. The suppression of GnRH leading to a decrease in sex hormones has been described as the principal mechanism of opioid-induced hypogonadism. However, there is no consensus on the threshold for the clinical diagnosis of hypogonadism. Evidence indicates that chronic opioid use can lead to hypogonadism. Clinicians should be aware of symptomatology associated with hypogonadism and should regularly monitor patients with appropriate laboratory investigations.