Adrenal Insufficiency

CLINICAL PRESENTATION

• Weight loss, dehydration, hyponatremia, hyperkalemia, and elevated blood urea nitrogen are common in Addison disease.
• Hyperpigmentation is common in Addison disease and may involve exposed and nonexposed parts of the body. Hyperpigmentation is usually not seen in secondary adrenal insufficiency because of low amounts of melanocyte-stimulating hormone.

DIAGNOSIS

• The short cosyntropin stimulation test can be used to assess patients with suspected hypocortisolism. An increase to a cortisol level of 18 mcg/dL or more (500 nmol/L) rules out adrenal insufficiency.
• Patients with Addison disease have an abnormal response to the short cosyntropin stimulation test. Plasma ACTH levels are usually 400 to 2000 pg/mL (88 to 440 pmol/L) in primary insufficiency versus normal to low (5–50 pg/mL [1.1–11 pmol/L]) in secondary insufficiency. A normal cosyntropin-stimulation test does not rule out secondary adrenal insufficiency.
• Other tests include the insulin hypoglycemia test, the metyrapone test, and the CRH stimulation test.

TREATMENT

Goals of Treatment: Limit morbidity and mortality, return the patient to a normal functional state, and prevent episodes of acute adrenal insufficiency.

Corticosteroids

• Hydrocortisone, cortisone, and prednisone are the glucocorticoids of choice, administered twice daily at the lowest effective dose while mimicking the normal diurnal adrenal rhythm of cortisol production.
• Recommended starting total daily doses are hydrocortisone 15 to 25 mg daily, which is approximately equivalent to cortisone acetate 25 to 37.5 mg, or prednisone 2.5 mg.
• Fludrocortisone acetate 0.05 to 0.2 mg orally once daily can be used to replace mineralocorticoid loss. If parenteral therapy is needed, 2 to 5 mg of deoxycorticosterone trimethylacetate in oil can be administered intramuscularly every 3 to 4 weeks. The major reason for adding the mineralocorticoid is to minimize development of hyperkalemia.