What is the recommended dose of Florinef (fludrocortisone) for a patient with Addison's disease and severely low cortisol levels?

Fludrocortisone Dosing for Addison's Disease

For a patient with Addison's disease and severely low cortisol levels (<0.03 μg/dL), start fludrocortisone at 0.05-0.1 mg once daily, with most patients requiring 0.1 mg daily as the standard maintenance dose. 1, 2

Initial Dosing Strategy

• Begin with fludrocortisone 0.1 mg once daily, which is the standard starting dose for primary adrenal insufficiency 1, 2
• The FDA-approved dosing range is 0.1 mg three times weekly to 0.2 mg daily, though 0.1 mg daily is most commonly used 1
• If transient hypertension develops, reduce the dose to 0.05 mg daily 1

Critical Concurrent Glucocorticoid Replacement

Fludrocortisone must always be administered alongside glucocorticoid replacement—never give mineralocorticoid replacement alone in Addison's disease. 1, 2

• Start hydrocortisone 15-25 mg daily in 2-3 divided doses (typically 10 mg + 5 mg + 2.5-5 mg) 2, 3
• Alternatively, use cortisone acetate 25-37.5 mg daily in divided doses 2
• The FDA label specifically recommends combining fludrocortisone with cortisone 10-37.5 mg daily or hydrocortisone 10-30 mg daily 1

Dose Titration and Monitoring

Adjust fludrocortisone based on clinical parameters, not laboratory cortisol levels, as the severely low cortisol (<0.03 μg/dL) indicates the need for immediate glucocorticoid replacement but doesn't directly determine mineralocorticoid dosing. 2

Monitor and titrate based on:

• Volume status and blood pressure: Reduce dose if hypertension develops; increase if persistent hypotension occurs 2, 1
• Serum sodium and potassium levels: Target normal electrolytes 2
• Plasma renin activity (PRA): Aim for the upper half of the reference range 2
• Salt cravings: Persistent cravings suggest under-replacement 2

Special Considerations for Severely Low Cortisol

Given the critically low cortisol level (<0.03 μg/dL), this patient likely requires urgent management:

• If symptomatic (Grade 2-4): Hospitalize and give hydrocortisone 100 mg IV bolus immediately, followed by 100 mg every 6-8 hours 2, 4
• Administer 0.9% saline 1-2 liters rapidly for volume resuscitation 2
• High-dose IV hydrocortisone (100 mg) provides mineralocorticoid effect by saturating 11β-HSD type 2 enzymes, temporarily eliminating the need for separate fludrocortisone during acute crisis 2
• Once stabilized on oral therapy (typically 5-7 days), initiate fludrocortisone 0.05-0.1 mg daily 2

Common Pitfalls to Avoid

• Never delay glucocorticoid treatment to obtain diagnostic testing when adrenal crisis is suspected—the mortality risk is significant 2, 4
• Do not use plasma ACTH or cortisol levels to adjust fludrocortisone dosing—these parameters are not useful for mineralocorticoid dose adjustment 2
• Avoid starting other hormone replacements before corticosteroids, as this can precipitate adrenal crisis by accelerating cortisol clearance 4
• Children and younger adults often require higher fludrocortisone doses than the standard 0.1 mg 3

Patient Education Requirements

All patients must receive:

• Medical alert identification (bracelet/necklace) 2, 3
• Steroid emergency card 2, 3
• Training on stress-dose adjustments (double or triple dose during illness) 3
• Emergency injectable hydrocortisone kit with administration training 2