What is the primary treatment for pituitary gland insufficiency?

Treatment of Pituitary Gland Insufficiency

The primary treatment for pituitary gland insufficiency is hormone replacement therapy, specifically targeting each deficient hormone with appropriate substitution therapy based on the affected pituitary axis. 1, 2, 3

Diagnosis and Assessment

Before initiating treatment, proper diagnosis is essential:

• Measure paired serum cortisol and plasma ACTH
• ACTH stimulation test (gold standard): administer 250 μg synthetic ACTH and measure cortisol at 0,30, and 60 minutes (peak cortisol <500 nmol/L confirms adrenal insufficiency) 1
• Assess all pituitary axes:
  • Corticotropic (ACTH)
  • Thyrotropic (TSH)
  • Gonadotropic (LH/FSH)
  • Somatotropic (GH)
  • Prolactin

Hormone Replacement Therapy

1. Corticotropic Axis (ACTH Deficiency)

• First priority for replacement due to life-threatening potential
• Hydrocortisone 15-25 mg daily in divided doses (first dose upon waking, last dose ≥6 hours before bedtime) 4, 1
• Alternative: Prednisone 5-7.5 mg daily 1
• Stress dosing protocol:
  • Minor illness/stress: Double or triple usual daily dose
  • Moderate stress: Hydrocortisone 50-75 mg/day in divided doses
  • Severe stress: Hydrocortisone 100 mg IV immediately, followed by 100-300 mg/day 1

2. Thyrotropic Axis (TSH Deficiency)

• L-thyroxine replacement (similar to primary hypothyroidism) 1, 2
• Important: Always start thyroid replacement after adequate cortisol replacement to avoid precipitating adrenal crisis

3. Gonadotropic Axis (LH/FSH Deficiency)

• Males: Testosterone replacement
• Females: Estrogen replacement therapy
• When fertility is desired, different approaches are needed (gonadotropins or pulsatile GnRH) 2

4. Somatotropic Axis (GH Deficiency)

• Growth hormone replacement:
  • Children: 0.18-0.3 mg/kg/week divided into daily doses 5
  • Adults: Individualized dosing after reevaluation if treated in childhood 5
• GH replacement improves quality of life, bone mass, and cardiovascular risk factors 6
• Prompt initiation of GH replacement is particularly important in children to promote catch-up growth and attain normal adult height 4

5. Posterior Pituitary (ADH Deficiency)

• Desmopressin for central diabetes insipidus 2

Special Considerations

Monitoring and Follow-up

• Annual clinical assessment including:
  • Weight and blood pressure measurement
  • Serum electrolytes
  • Assessment for development of new autoimmune disorders (particularly hypothyroidism)
  • Bone mineral density every 3-5 years 4

Patient Education

• All patients should:
  • Wear medical alert identification
  • Carry a steroid alert card
  • Have emergency hydrocortisone injection kit
  • Receive education on managing daily medications and minor illnesses 1

Adrenal Crisis Management

• Immediate IV/IM hydrocortisone 100 mg, followed by 100 mg every 6-8 hours until recovered
• Fluid resuscitation with isotonic saline (initial rate 1 L/hour until hemodynamic improvement)
• Identify and treat underlying precipitant 4, 1

Cautions and Pitfalls

1. Never delay treatment of suspected acute adrenal insufficiency for diagnostic procedures 4
2. Fundoscopic examination should be performed before initiating GH therapy to exclude preexisting papilledema 5
3. GH therapy should be discontinued once epiphyseal fusion has occurred in children 5
4. Careful monitoring for tumor recurrence is needed when using GH replacement in patients with history of pituitary tumors, though current evidence does not show increased recurrence risk 6

Hormone replacement therapy for pituitary insufficiency is typically lifelong and requires regular monitoring to ensure optimal dosing and prevent complications 7.