Fludrocortisone Dosage and Management in Primary Adrenal Insufficiency
Most patients with primary adrenal insufficiency should take 50-200 μg fludrocortisone as a single daily dose, with children and younger adults potentially requiring higher doses. 1
Standard Dosing Recommendations
- Initial dosage: 0.1 mg (100 μg) fludrocortisone daily 2
- Dosage range: 0.05-0.2 mg daily, or as specific as:
- 0.1 mg daily (standard dose)
- 0.1 mg three times weekly (lower end)
- 0.2 mg daily (higher end) 2
Dosage Adjustment Factors
Clinical Parameters to Monitor
- Blood pressure (standing and supine)
- Serum electrolytes (sodium and potassium)
- Plasma renin activity (PRA) - aim for upper normal range 3
- Salt craving
- Presence of peripheral edema
- Overall sense of well-being
Dose Reduction Needed When:
- Hypertension develops (reduce to 0.05 mg daily) 2
- Essential hypertension develops (reduce dose but do not stop) 1
Dose Increase Needed When:
- Hypotension persists
- Hyperkalemia occurs
- Hyponatremia occurs
- Salt craving continues
- Elevated plasma renin activity 4
Special Populations
Children and Young Adults
- May require higher doses than adults 1
- Dosing should be adjusted based on clinical response and laboratory parameters
Pregnancy
- Dose adjustments often needed during pregnancy, particularly in the last trimester
- Increased requirements due to anti-mineralocorticoid effects of progesterone 1, 3
- Monitor blood pressure, electrolytes, and symptoms closely
Hot Weather/High Temperature
- May need dose adjustments in high ambient temperatures to avoid sodium depletion 3
Administration Guidelines
- Administer as a single daily dose, preferably in the morning 2
- Always administer in conjunction with glucocorticoid replacement (typically hydrocortisone 15-25 mg daily in divided doses) 1, 5
- Patients should be advised to consume salt and salty foods freely 1
- Avoid licorice and grapefruit juice (can potentiate mineralocorticoid effects) 1
Monitoring Protocol
Regular Assessment
- Annual review at minimum 1
- Measure weight, blood pressure, and serum electrolytes
- Consider plasma renin activity measurements to guide dosing 4, 3
Medication Interactions
Adjust fludrocortisone dosing when patients are on:
- Diuretics
- NSAIDs
- Carbenoxolone
- Drospirenone-containing contraceptives 1
Special Considerations
Surgery and Medical Procedures
- Continue fludrocortisone during minor procedures
- For major surgery, restart when hydrocortisone dose falls below 50 mg/day 1
Adrenal Crisis Management
- Focus on hydrocortisone and fluid replacement during crisis
- Resume fludrocortisone once stabilized on maintenance hydrocortisone 1
Long-term Follow-up
- Some patients may require dose reduction over time (particularly after >60 months of treatment) 4
- Regular monitoring remains essential even in stable patients
By following these guidelines for fludrocortisone dosing and monitoring, patients with primary adrenal insufficiency can achieve optimal mineralocorticoid replacement, reducing morbidity and mortality associated with this condition.