Case Challenge: Chronic Opioid Use Causing Adrenal Insufficiency
Her initial vital signs on admission to the hematology floor were: blood pressure, 91/54 mmHg; pulse, 98 beats per minute; respiratory rate, 18 breaths per minute; afebrile; and oxygen saturation of 99%. She was in mild distress due to pain. Her lungs were clear to auscultation, her abdomen was soft and nontender, and her heart had a regular rate and rhythm. She had tenderness to palpation in all 4 extremities. An initial work up included a complete blood count (CBC), complete metabolic panel (CMP), chest x-ray, urinalysis, and blood cultures.
The results of the patient’s CBC displayed a white blood cell count of 11,000 cells/mcL, hemoglobin of 8.2 g/dL, hematocrit of 24%, and platelet (thrombocyte) count of 484,000/mcL. Her CMP and chest x-ray were unremarkable. Blood glucose was 84 mg/dL. Blood cultures were negative after 2 days, and urinalysis was unremarkable.
During the patient’s sickle cell crises, she typically receives intravenous hydromorphone (1 mg every 2 h) until the pain subsides over a course of 5 to 7 days and she is typically sent home with oral hydromorphone for 1 to 2 weeks. The patient reports that the extended-release morphine sulfate 45 mg twice a day shortens her hospital stay. The patient reports that prior to starting morphine sulfate, she would be in the hospital for approximately 2 weeks during each sickle cell crisis.
During her latest hospitalization, the patient was given fluids, antiemetics, and analgesics. Despite receiving fluid for 2 days, she continued to have persistent hypotension and vomiting.
Given the patient’s low blood pressure, an adrenal insufficiency work up was ordered. A morning cortisol level was taken, and came back at 4.2 mcg/dL (normal 5-23 mcg/dL); the adrenalcorticotrophic hormone (ACTH) level was 11 pg/mL (normal 9-52 pg/mL), and she had a normal response to a consyntropin stimulation test. A brain MRI was performed, which was unremarkable and displayed a normal pituitary gland. Given this data, a diagnosis of secondary adrenal insufficiency was made. Other causes of secondary adrenal insufficiency were ruled out, at which point the cause was attributed to chronic use of opioids—morphine sulfate and hydromorphone.
The patient was started on intravenous hydrocortisone (100 mg every 6 h) and her symptoms resolved. She was able to be discharged and was prescribed oral hydrocortisone (20 mg in morning and 10 mg at night). In addition, she was given hydromorphone 1 mg to take as needed and morphine sulfate 15 mg twice a day. Within 3 months of treatment, her menstrual cycle returned. Six months later, she was successfully weaned off the long-acting opioids. She continued having sickle cell crises during this time and was treated with intravenous fluids and short-acting opioids during her attacks.
Opioid endocrinopathy (OE) has been documented as early as the 18th century by Charles Alexander Bruce, an English explorer who was the father of the tea industry in India; Bruce stated that opium is causing the “feeble opium-smokers of Assam” to be “more effeminate than women.”1 With the increased use of opioids for chronic pain, the incidence of opioid endocrinopathy is rising. However, it remains relatively unknown among physicians. OE is a dysfunction in the hypothalamic-pituitary tracts affecting the sex and adrenal hormones. OE can produce a myriad of symptoms (Table 1). The symptoms can be subtle, which makes it difficult to diagnose without screening and diagnostic testing.
The hypothalamic-pituitary-gonadal tract is responsible for producing sex hormones in humans. The hypothalamus releases gonadotropin-releasing hormone (GnRH), which targets the pituitary gland, releasing luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH stimulate the testes and ovaries to produce testosterone and estrogen, respectively. Opioids bind to receptors on the hypothalamus and pituitary, inhibiting the release of GnRH and LH (Figure 1).2,3
As a result, hypogonadism can be seen in both males and females—producing the symptoms described in Table 1. One study has shown that naloxone, an opiate antagonist, was found to increase LH and increase testosterone days later.3 In rat studies, opioids have a direct effect on the testes, causing decreased levels of testosterone and testicular interstitial fluid.4
The hypothalamic-pituitary-adrenal (HPA) axis also is affected by opioids as demonstrated by this case. Opioids inhibit the release of corticotrophin-
releasing hormone from the hypothalamus, preventing the release of ACTH from the anterior pituitary gland.2 As a result, cortisol—a hormone responsible for homeostasis of the stress response, blood sugar, and blood pressure—is decreased. Also, the HPA axis is responsible for producing dehydro-
epiandrosterone (DHEA), a precursor for estrogen and testosterone. Opioids typically do not affect cortisol levels, although there have been case reports and studies showing that opioids suppress cortisol.5-10
The case presented is that of a young woman with sickle cell anemia who was on chronic opioids. She was found to have opioid-induced endocrinopathy that affected her hypothalamic pituitary adrenal tract and caused a decrease in cortisol. Her primary care physician prescribed extended-release morphine sulfate to manage the pain of her numerous sickle cell attacks (20 per year).
Her HPA axis was disturbed as a result of her being on 90 mg of morphine equivalents along with intermittent hydromorphone over a 3-year period. Her cortisol level was suppressed, which affected her ability to respond to fluids given for hypotension. The patient’s amenorrhea could be caused by either suppression of the HPG tract or the inability of the HPA tract to produce DHEA. We did not get any hormonal testing, such as a LH, FSH, estradiol, testosterone, or DHEA sulfate level, because she had a great response to treatment.