What investigations should be done in a patient who has discontinued long-term oral corticosteroids (steroids)?

Investigations for Patients Discontinuing Long-Term Oral Steroids

All patients who have discontinued long-term oral steroids should undergo an ACTH stimulation test to assess for adrenal insufficiency, as approximately 50% will have some degree of hypothalamic-pituitary-adrenal (HPA) axis suppression that may persist for months after discontinuation. 1

Primary Assessment: HPA Axis Function

ACTH Stimulation Test

• Low-dose (1 μg) ACTH stimulation test is the gold standard for confirming adrenal insufficiency 2, 3
  • Measure cortisol at 0,30, and 60 minutes after ACTH administration
  • Peak cortisol <500 nmol/L confirms adrenal insufficiency 2
  • This test should be performed 4 weeks after tapering to physiologic doses 4

Morning Cortisol Level

• Measure 8:00 AM serum cortisol level
• Morning cortisol <5 μg/dL suggests severe adrenal insufficiency 3
• Note: Morning cortisol levels in patients with normal HPA reserve and partial hypoadrenalism overlap considerably, making this test alone insufficient 3

Additional Investigations

Electrolyte Panel

• Check serum sodium and potassium
• Hyponatremia and hyperkalemia may indicate mineralocorticoid deficiency in primary adrenal insufficiency 2

Blood Pressure and Orthostatic Measurements

• Measure blood pressure sitting and standing
• Orthostatic hypotension may indicate adrenal insufficiency 5

Clinical Assessment

• Evaluate for symptoms of adrenal insufficiency:
  • Fatigue, weakness
  • Nausea, vomiting, abdominal pain
  • Dizziness, especially when standing
  • Weight loss
  • Salt craving

Follow-up Testing

• For patients with confirmed adrenal insufficiency, repeat ACTH stimulation test every 3-6 months until normalization
• 50% of patients with adrenal suppression show recovery by 7 months, but some may have persistent suppression for 12 months or longer 4

Rationale for Testing

1. High prevalence: Approximately 60% of patients on long-term steroids develop adrenal suppression 3

2. Unpredictable recovery: Duration of adrenal suppression does not consistently correlate with steroid dose or duration of therapy 6

3. Risk of adrenal crisis: Undiagnosed adrenal insufficiency can lead to life-threatening adrenal crisis during stress, illness, or surgery 2, 7

4. Impact on quality of life: Adrenal insufficiency significantly affects patients' wellbeing and daily functioning 1

Important Considerations

• Adrenal suppression can persist for months to years after steroid discontinuation, even with gradual tapering 4
• Higher maximum glucocorticoid doses are a significant predictor for developing adrenal suppression 4
• Patients with severe adrenal suppression should not have steroids completely withdrawn 3
• Patients with partial adrenal suppression may require stress-dose steroids during illness, surgery, or significant physical stress 2, 3

Common Pitfalls to Avoid

• Relying solely on morning cortisol: This is insufficient to rule out adrenal insufficiency 3
• Assuming recovery based on duration: Some patients have persistent suppression for 2+ years 4
• Failing to educate patients: All patients with confirmed adrenal insufficiency need education about stress dosing and medical alert identification 2
• Missing non-specific symptoms: Symptoms of adrenal insufficiency can be vague and overlap with other conditions 1

By conducting these investigations systematically, clinicians can identify patients at risk for adrenal insufficiency and implement appropriate management strategies to prevent potentially life-threatening adrenal crisis.