Adrenal Insufficiency

SOURCE

Source: Hwang AY, Smith SM, Gums JG. Adrenal gland disorders. In: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM, eds. Pharmacotherapy: A Pathophysiologic Approach. 10th ed. New York, NY: McGraw-Hill; 2017. http://accesspharmacy.mhmedical.com/content.aspx?bookid=1861&sectionid=134128262. Accessed March 14, 2017.

CONDITION/DISORDER SYNONYMS

• Addison disease.

DEFINITION

• Hypofunction of adrenal gland caused by primary (Addison disease) or secondary adrenal insufficiency.

ETIOLOGY

• Autoimmune dysfunction (eg, Graves disease)

• Autoimmune polyendocrine syndrome.

• Tuberculosis.

• Bilateral adrenalectomy.

• Medications (ketoconazole, phenytoin, rifampin, phenobarbital)

PATHOPHYSIOLOGY

• Occurs when adrenal glands do not produce enough cortisol and, in some cases, aldosterone.

• Primary adrenal insufficiency (Addison disease) usually causes:

  • Destruction of all regions of adrenal cortex.

  • Deficiencies of cortisol, aldosterone, and androgens.

  • Compensatory increases in corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH)

• Autoimmune dysfunction causes 80–90% of cases in developed countries; tuberculosis is leading cause in developing countries.

• Medications that inhibit cortisol synthesis (eg, ketoconazole) or accelerate cortisol metabolism (eg, phenytoin, rifampin, phenobarbital) can also cause primary adrenal insufficiency.

• Secondary adrenal insufficiency usually results from exogenous corticosteroid use, leading to suppression of hypothalamic-pituitary-adrenal axis and decreased ACTH release, resulting in impaired androgen and cortisol production.

EPIDEMIOLOGY

• Incidence approximately 1 in 100,000

• Can affect persons of any age, gender, or ethnicity but typically presents in adults between ages 30 and 50 years.

CLINICAL PRESENTATION

SIGNS AND SYMPTOMS

• Weight loss, weakness, craving for salt, headaches, memory impairment, depression, postural dizziness, and GI symptoms.

• Early symptoms of acute adrenal insufficiency also include myalgias, malaise, and anorexia, which can eventually lead to vomiting, fever, and shock.

• Hyperpigmentation may involve exposed and nonexposed body parts.

DIAGNOSIS

LABORATORY TESTS

• Using the short cosyntropin stimulation test, an increase in cortisol level to 18 mcg/dL (500 nmol/L) or more rules out adrenal insufficiency.

• Patients with Addison disease have an abnormal response to the short cosyntropin stimulation test. Plasma ACTH levels are usually 400–2000 pg/mL in primary insufficiency and normal to low (5–50 pg/mL) in secondary insufficiency.

• A normal cosyntropin-stimulation test does not rule out secondary adrenal insufficiency.

• Insulin hypoglycemia test, metyrapone test, and CRH stimulation test are sometimes performed.

DESIRED OUTCOMES

• Limit morbidity and mortality.

• Return patient to normal function.

• Prevent episodes of acute adrenal insufficiency.

TREATMENT: NONPHARMACOLOGIC THERAPY

• Inform patients of expected outcome, treatment complications, proper medication use and adherence, and potential side effects.

TREATMENT: PHARMACOLOGIC THERAPY FOR ADRENAL INSUFFICIENCY

• Corticosteroids (Table 1)

  • Use hydrocortisone, cortisone, or prednisone at the lowest effective dose twice daily to mimic ...