What is the treatment for a patient with adrenal insufficiency confirmed by low cortisol levels after a cosyntropin (adrenocorticotropic hormone, ACTH) stimulation test?

Treatment for Adrenal Insufficiency Confirmed by Low Cortisol After Cosyntropin Test

Patients with adrenal insufficiency confirmed by low cortisol levels after cosyntropin testing require immediate glucocorticoid replacement with hydrocortisone 15-20 mg daily in divided doses (typically 2/3 in morning, 1/3 in early afternoon), with additional fludrocortisone 0.05-0.1 mg daily for primary adrenal insufficiency. 1

Immediate Management

For Non-Emergency Situations:

• Start oral hydrocortisone 15-20 mg total daily dose in divided doses:
  • Morning dose: 10-15 mg (2/3 of total dose)
  • Afternoon dose: 5-10 mg (1/3 of total dose)
• Maximum of 30 mg daily may be used for residual symptoms 1
• Hydrocortisone is preferred over prednisone or dexamethasone due to its shorter half-life and better mimicry of natural cortisol rhythm 1

For Emergency/Adrenal Crisis:

• Administer immediate IV hydrocortisone 100 mg or dexamethasone 4 mg if diagnosis is not yet confirmed 2
• Provide at least 2L of normal saline IV 2, 1
• Continue IV hydrocortisone 50-100 mg every 6-8 hours until stabilized 1
• Taper to oral maintenance doses over 5-10 days 2, 1

Mineralocorticoid Replacement

• For primary adrenal insufficiency: Add fludrocortisone 0.05-0.1 mg daily 1
• Adjust based on:
  • Blood pressure
  • Electrolyte levels (sodium, potassium)
  • Plasma renin activity (target upper half of reference range) 1
• Not typically needed for secondary adrenal insufficiency (pituitary origin) 2

Patient Education and Monitoring

Essential Education:

1. Provide medical alert bracelet/necklace for adrenal insufficiency 2, 1
2. Educate on stress dosing:
   • Minor illness/stress: Double daily dose
   • Major illness/surgery: IV hydrocortisone required 1
3. When to seek emergency care for impending adrenal crisis 1

Monitoring:

• Regular blood pressure measurements
• Periodic electrolyte checks
• Weight monitoring
• Assessment for symptoms of under-replacement (fatigue, nausea, hypotension) or over-replacement (weight gain, hypertension, edema) 1

Special Considerations

Distinguishing Primary vs. Secondary Adrenal Insufficiency:

• Primary: Low cortisol with high ACTH
• Secondary: Low cortisol with low/inappropriately normal ACTH 2, 1

Additional Testing:

• For secondary adrenal insufficiency: Evaluate for other pituitary hormone deficiencies
  • TSH, FT4
  • LH, FSH, testosterone/estradiol
  • Consider pituitary MRI 2

Common Pitfalls to Avoid:

1. Tapering corticosteroids too rapidly can precipitate adrenal crisis 1
2. Failing to educate patients about stress dosing 1
3. Using long-acting glucocorticoids (prednisone, dexamethasone) for replacement therapy 1
4. Not recognizing steroid withdrawal syndrome 1
5. Starting thyroid hormone replacement before corticosteroids in patients with multiple hormone deficiencies 2

Long-term Management

• Obtain endocrine consultation for ongoing management 2, 1
• Mandatory endocrine consultation before surgery or high-stress treatments 1
• Lifelong replacement therapy is typically required 1
• Regular clinical assessment and periodic laboratory monitoring 1

The management of adrenal insufficiency requires careful attention to dosing, patient education, and monitoring to prevent both under-replacement (risking adrenal crisis) and over-replacement (causing Cushing-like symptoms). While the diagnosis can be challenging 3, proper treatment significantly improves outcomes and quality of life for patients with this condition 4.