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Effects of Opioids and Cannabis on the Endocrine System by Dr. Stan Van Uum

Effects of Opioids and Cannabis on the Endocrine System by Dr. Stan Van Uum

January 17, 2019 – Bethany Monteith, MD, FRCPC, MSc (Translational Medicine) Candidate

Effects of Opioids and Cannabis on the Endocrine System by Dr. Stan Van Uum

In the 1990’s healthcare providers started to prescribe opioids at a greater rate alongside reassurance from the pharmaceutical industry that patients would not become addicted.  With an abundance of prescription opioids on the market, many of these were diverted to the streets and misuse began to grow.  Rates of substance use disorders and death from opioid-overdose have skyrocketed in the last two decades.  Now North America uses 70% of the world’s opioid supply – including prescription opioids, heroin, and synthetic fentanyl.  The opioid epidemic has been declared a public health emergency with 42,000 estimated American deaths in 2017 (U.S. Department of Health and Human Services, 2018).

Opioids are most commonly prescribed for chronic non-cancer pain and it is estimated that one in 10 patients with an opioid prescription will develop a substance use disorder.  The majority of heroin users report having used prescription opioids as their first opioid exposure.  Paradoxically, chronic opioid use can lead to unanticipated side-effects including hyperalgesia, immunosuppression, and hypogonadism.  Opioid-induced hypogonadism further exacerbates the pain cycle by decreasing the relative analgesic effects of opioids, in part, through suppression of the hypothalamic-pituitary-gonadal axis.

Dr. Stan Van Uum is an endocrinologist, translational medicine researcher, and associate professor at Western University in London, Ontario.  His work on opioid-induced hypogondasim demonstrates that chronic opioid use results in decreased levels of luteinizing hormone, testosterone, estradiol, and oxytoxin and increased levels of growth hormone and prolactin.   For men using opioids, it is estimated that 85–90% have associated hypogonadism leading to symptoms of delayed ejaculation, erectile dysfunction, and decreased libido.  A chronic state of hypogonadism may progress to decrease bone mineral density, osteopenia, and osteoporosis and an increased risk of osteoporotic fracture.  It is hypothesized that chronic opioid use alters the normal gonadotropin pulse pattern and affects the response of the anterior pituitary to GnRH resulting in decreased testosterone levels. Morphine may also down regulate estrogen receptor beta in vascular endothelial cells. 

In this week’s Queen’s University Medical Grand Rounds, Dr. Van Uum encouraged all physicians to screen for symptoms of hypogonadism in both male and female patients. Blood tests looking for altered levels of FSH, LH, testosterone, estrogen should be obtained to confirm a hormone deficiency. Hormone replacement therapy with topical testosterone and estrogen is very effective at reversing the effects of opioid-induced hypogonadism and may decrease the amount of opioid required to achieve adequate pain control.

The effects of cannabis on the endocrine system are not well understood. Aside from an influential and frequently sited paper in The New England Journal from 1974, there is little scientific data to support or refute the detrimental effects of cannabis on the endocrine system including fertility and testosterone levels.  In the lay press, opinions on both sides of the argument can easily be found, but until robust scientific experiments are reported, it remains difficult to council patients on the effects that cannabis may have on endocrine function, including reproductive health and well-being.  

Comments

Name
Paula James

Wed, 01/23/2019 - 11:07

I found this round so interesting - and you've done a great job with the post, Bethany!

Name
Paula James

Name
Kathleen

Thu, 02/14/2019 - 08:54

Excellent review Bethany. This speaks to the importance of the opioid crisis, and secondary complications related to opioid prescription.

Name
Kathleen

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