From the Guidelines
The workup for possible adrenal deficiency should begin with evaluating AM levels of ACTH and cortisol level, as well as a basic metabolic panel, renin, and aldosterone, as recommended by the most recent guidelines 1. When evaluating a patient for adrenal deficiency, it is essential to consider the relationship between ACTH and cortisol levels. Key steps in the workup include:
- Evaluating AM levels of ACTH (if > 23 ULN) and cortisol level (if < 3 mg/dL) 1
- Basic metabolic panel (Na, K, CO2, and glucose) to assess for electrolyte imbalances and other metabolic disturbances
- Renin and aldosterone levels to evaluate the renin-angiotensin-aldosterone system
- Consideration of a standard dose ACTH stimulation test for indeterminate results (AM cortisol < 3 mg/dL and < 15 mg/dL) 1
- Evaluation for precipitating causes of crisis, such as infection
- Adrenal CT for metastasis or hemorrhage, which are common causes of primary adrenal insufficiency 1 In cases where adrenal crisis is suspected, emergent therapy with hydrocortisone 100 mg IV should be initiated immediately, even before diagnostic confirmation, as this condition can be life-threatening 1. It is also crucial to educate patients on stress dosing and provide them with a medical alert bracelet for adrenal insufficiency to trigger stress-dose corticosteroids by EMS, as well as to consult with an endocrinologist prior to surgery or any procedure for stress-dose planning 1.
From the FDA Drug Label
INDICATIONS & USAGE Fludrocortisone acetate tablets, 0.1 mg are indicated as partial replacement therapy for primary and secondary adrenocortical insufficiency in Addison’s disease and for the treatment of salt-losing adrenogenital syndrome. The FDA drug label does not answer the question.
From the Research
Diagnostic Approach
The workup for possible adrenal deficiency involves a combination of clinical assessment and biochemical tests. The diagnosis of adrenal insufficiency is based on demonstrating low basal and/or stimulated serum cortisol levels 2. A short corticotropin test (250 μg) is considered the "gold standard" diagnostic tool to establish the diagnosis 3.
Laboratory Tests
Laboratory tests used to diagnose adrenal insufficiency include:
- Basal hormone level measurements
- Stimulation tests, such as the short corticotropin test
- Measurement of morning plasma adrenocorticotropic hormone (ACTH) and cortisol levels 3
- Validated assay of autoantibodies against 21-hydroxylase to diagnose the underlying cause 3
Clinical Features
Clinical features that may indicate adrenal insufficiency include:
- Unintentional weight loss
- Anorexia
- Postural hypotension
- Profound fatigue
- Muscle and abdominal pain
- Hyponatraemia
- Skin hyperpigmentation (in primary adrenal insufficiency)
- Salt cravings (in primary adrenal insufficiency) 4
Management
Management of adrenal insufficiency involves:
- Glucocorticoid replacement therapy, typically with hydrocortisone or cortisone acetate 2, 5, 3
- Mineralocorticoid replacement therapy in patients with primary adrenal insufficiency 2, 3
- Patient education on managing adrenal insufficiency, including stress dosing and emergency administration of glucocorticoids 3, 4
- Regular monitoring for features of under- and over-replacement 2