The report, “Etomidate in the control of severe Cushing’s syndrome by neuroendocrine carcinoma,” appeared in the journal Clinical Case Reports.
The investigators reported the case of a 51-year-old woman with ectopic Cushing’s syndrome caused by a pancreatic tumor. Ectopic Cushing’s refers to cases of excess secretion of adrenocorticotropin hormone (ACTH) outside the pituitary or adrenal glands.
The patient underwent distal pancreatectomy — the surgical removal of the bottom half of the pancreas — in 2015 due to an ACTH-secreting tumor. Although she had a good initial response, liver metastasis was evident by 2016.
Compared to measurements in 2016, morning blood cortisol, 24-hour urinary-free cortisol, and ACTH levels significantly increased in 2017. The patient also showed low levels of the luteinizing and follicle-stimulating hormones, which the scientists attributed to her severe hypercortisolism (excess cortisol levels).
The woman was being treated with ketoconazole to lower her cortisol values and later received chemoembolization — a method to reduce blood supply and deliver chemotherapy directly to a tumor — for her liver metastasis.
Although ketoconazole is generally the treatment of choice for the control of hormone production in the adrenal glands, its effectiveness is often limited and is associated with side effects, clinicians noted.
In April 2017, the patient arrived at the emergency room with sepsis — a potentially life-threatening complication of an infection — that originated in the gut.
Because ketoconazole had failed to lower cortisol levels, the patient started receiving infused etomidate, an inhibitor of the enzyme 11‐beta‐hydroxylase that prevents cortisol synthesis.
This treatment was stopped one day before the bilateral removal of the adrenal glands as a definitive treatment for the elevated production of cortisol.
While the patient experienced decreased levels of potassium, calcium, and magnesium with an initial dose of 0.04 mg per kg body weight an hour of etomidate, a gradual decrease of etomidade — depending on her cortisol levels — corrected these alterations.
After surgery, the patient showed a significant improvement in her general health, including control of her sepsis. She is currently taking hydrocortisone and fludrocortisone, with treatment for liver metastasis pending.
“Etomidate is a very effective drug in severe Cushing’s syndrome that is refractory to ketoconazole,” the researchers wrote.
“Control of the serum cortisol levels in ectopic Cushing’s syndrome can be obtained with infusion rates much lower than those used in anesthesia, without respiratory side effects,” they added.
The authors recommend an initial dose of etomidate of 0.04 mg/kg per hour, daily monitoring of 24-hour urinary cortisol and cortisol levels, and a gradual decrease of the etomidate dose according to daily measurements of metabolites.