What is the recommended treatment for adrenal insufficiency in patients with Facioscapulohumeral muscular dystrophy (FSHD)?

Treatment of Adrenal Insufficiency in Patients with Facioscapulohumeral Muscular Dystrophy (FSHD)

The recommended treatment for adrenal insufficiency in patients with FSHD follows the same principles as for any patient with primary adrenal insufficiency: hydrocortisone 15-25 mg daily in divided doses plus fludrocortisone 50-200 μg as a single daily dose, with dose adjustments based on clinical response and laboratory parameters. 1

Glucocorticoid Replacement Therapy

• Most patients with primary adrenal insufficiency should receive 15-25 mg of hydrocortisone (or 18.75-31.25 mg of cortisone acetate) daily in split doses 1
• The first dose should be taken immediately after waking, and the last dose not less than 6 hours before bedtime to mimic the natural circadian rhythm 1
• The lowest dose compatible with health and a sense of well-being should be used to minimize side effects 1
• For children, hydrocortisone dosing should be 6-10 mg per m² of body surface area 1

Mineralocorticoid Replacement Therapy

• Most patients with primary adrenal insufficiency should take 50-200 μg fludrocortisone as a single daily dose in the morning 1, 2
• Children and younger adults may require higher doses (up to 500 μg daily) 2
• Dose adjustments should be based on: 2
  • Blood pressure measurements in both supine and standing positions
  • Serum electrolytes (sodium and potassium)
  • Clinical symptoms such as salt cravings or lightheadedness

Monitoring and Dose Adjustments

• If essential hypertension develops, the fludrocortisone dose should be reduced but not completely stopped 1, 2
• Under-replacement with fludrocortisone is common and may predispose patients to recurrent adrenal crises 2
• Patients should be advised to take salt and salty foods ad libitum 1
• Avoid liquorice and grapefruit juice as they potentiate the mineralocorticoid effect of hydrocortisone 2

Management of Adrenal Crisis

• Adrenal crisis should be treated immediately with intravenous or intramuscular hydrocortisone, 100 mg followed by 100 mg every 6-8 hours until recovered 1
• Isotonic (0.9%) sodium chloride solution should be administered at an initial rate of 1 L/hour until hemodynamic improvement 1
• The underlying precipitant of adrenal crisis (e.g., infection) should be identified and treated 1

Patient Education and Crisis Prevention

• All patients should wear Medic Alert identification jewelry and carry a steroid/alert card 1
• Patients should receive sufficient education to manage daily medications and situations of minor to moderate concurrent illnesses 1
• Supplies to allow self-injection of parenteral hydrocortisone should be provided 1
• Surgery and invasive medical procedures often require intravenous or intramuscular hydrocortisone and increased oral doses 1

Follow-up Care

• Patients should be reviewed at least annually, with assessment of health and well-being, measurement of weight, blood pressure, and serum electrolytes 1
• Occasional monitoring for the development of new autoimmune disorders, particularly hypothyroidism, is worthwhile 1
• Assessment for the complications of glucocorticoid therapy should include monitoring of bone mineral density every 3-5 years 1

Special Considerations for FSHD Patients

While there are no specific guidelines for adrenal insufficiency treatment in FSHD patients, clinicians should be aware that:

• Muscle weakness from FSHD may mask some symptoms of adrenal insufficiency 3
• Careful attention to mineralocorticoid replacement is essential as orthostatic hypotension may worsen mobility issues in FSHD patients 2
• The stress of managing a chronic neuromuscular condition may require vigilant monitoring of glucocorticoid adequacy 3

Common Pitfalls to Avoid

• Delaying treatment in suspected acute adrenal insufficiency while waiting for test results 4
• Stopping fludrocortisone completely when hypertension develops (reduce dose instead) 2
• Failing to adjust glucocorticoid doses during periods of illness, surgery, or other stressors 1
• Underestimating the importance of patient education in preventing adrenal crises 1