Management of Secondary Adrenal Insufficiency
Diagnostic Approach
- Low ACTH with low cortisol is diagnostic of secondary adrenal insufficiency, distinguishing it from primary adrenal insufficiency (which presents with high ACTH and low cortisol) 1, 2
- Evaluate morning ACTH and cortisol levels, along with basic metabolic panel to check for electrolyte abnormalities 1, 3
- Assess for other pituitary hormone deficiencies: TSH, FT4, LH, FSH, testosterone/estradiol 1, 4
- Consider MRI of the brain with pituitary/sellar cuts in patients with multiple endocrine abnormalities or new severe headaches 1, 4
Etiology Assessment
- Immune checkpoint inhibitor therapy can cause hypophysitis, leading to secondary adrenal insufficiency 1, 4
Treatment Algorithm
- Initiate hormone replacement with hydrocortisone 10-20 mg orally in the morning and 5-10 mg in early afternoon for mild symptoms 1
- Consider endocrine consultation for optimization of therapy 1
- If multiple hormone deficiencies are present, always start corticosteroids several days before thyroid hormone to prevent precipitating adrenal crisis 1, 3
- For moderate symptoms, consider higher initial dosing: hydrocortisone 20-30 mg in the morning and 10-20 mg in the afternoon 1, 5
- Taper stress-dose corticosteroids down to maintenance doses over 5-10 days for moderate symptoms 1, 5
- For severe symptoms or adrenal crisis, administer IV normal saline and IV stress-dose corticosteroids (hydrocortisone 100 mg or dexamethasone 4 mg) 1, 4
- Taper stress-dose corticosteroids down to maintenance doses over 7-14 days after discharge for severe symptoms or adrenal crisis 1, 4
Long-term Management
- Maintenance therapy with hydrocortisone 10-20 mg in the morning and 5-10 mg in early afternoon 1
- Educate patients on stress dosing (doubling or tripling doses during illness, surgery, or significant stress) 1, 3
- Provide medical alert bracelet for adrenal insufficiency to trigger stress-dose corticosteroids by emergency services 1, 3
- Endocrine consultation prior to surgery or any procedure for stress-dose planning 1, 3
Special Considerations
- If other pituitary hormone deficiencies are present, replacement therapy should be initiated with corticosteroids first, followed by other hormones 1, 3
- For patients on thyroid hormone replacement, follow FT4 for dose titration as TSH is not accurate 1, 3