What is the recommended treatment and dosage for patients with adrenal insufficiency using Florinef (fludrocortisone)?

Fludrocortisone Treatment for Adrenal Insufficiency

Standard Dosing Regimen

For primary adrenal insufficiency, fludrocortisone should be initiated at 0.1 mg once daily in the morning, with most patients requiring 50-200 μg daily as a single dose, adjusted based on blood pressure, serum electrolytes (sodium and potassium), and clinical symptoms such as salt craving and orthostatic hypotension. 1, 2

• The FDA-approved starting dose is 0.1 mg daily, though the dosing range extends from 0.1 mg three times weekly up to 0.2 mg daily 1
• Children and younger adults may require higher doses, up to 500 μg daily 2
• The medication should be taken as a single morning dose upon awakening 2

Combination Therapy Requirements

Fludrocortisone must always be combined with glucocorticoid replacement therapy in primary adrenal insufficiency. 1, 3, 4

• Hydrocortisone 10-30 mg daily in divided doses (typically 10-20 mg in the morning, 5-10 mg in early afternoon) 3, 1
• Alternative: Cortisone acetate 10-37.5 mg daily in divided doses 1
• Alternative: Prednisone 5-10 mg daily 3

Dose Adjustment Algorithm

Increase Fludrocortisone When:

• Hyponatremia is present 2
• Hyperkalemia develops 2
• Orthostatic hypotension persists despite adequate sodium intake 2
• Salt craving continues 2
• Postural dizziness occurs 2

Decrease Fludrocortisone When:

• Hypertension develops (reduce dose but do not discontinue completely) 2, 1
• Peripheral edema appears 2
• If transient hypertension occurs, reduce to 0.05 mg daily 1

Critical Monitoring Parameters

Monitor blood pressure in both supine and standing positions, serum sodium, serum potassium, and plasma renin activity at least annually. 2, 5

• Target normotension and normokalemia 2, 5
• Aim for plasma renin activity in the upper normal range 5, 6
• Weight should be assessed at each visit 2

Important Clinical Considerations

Under-replacement with fludrocortisone is common and may predispose patients to recurrent adrenal crises. 2, 5

• Many patients with PAI remain symptomatic despite standard dosing, suggesting inadequate mineralocorticoid replacement 5
• Patients should be advised to consume salt and salty foods ad libitum 2
• Avoid potassium-containing salt substitutes marketed as "healthy" 2

Medication and Dietary Interactions

Avoid liquorice and grapefruit juice as they potentiate the mineralocorticoid effect of hydrocortisone. 2

• Diuretics, acetazolamide, carbenoxolone, and NSAIDs should be avoided due to interactions with fludrocortisone 2
• Drospirenone-containing contraceptives may require higher fludrocortisone doses 2
• Pregnancy, particularly in the third trimester, may require increased fludrocortisone due to progesterone's anti-mineralocorticoid effects 2

Critical Safety Warning

Never abruptly discontinue fludrocortisone, as this can trigger adrenal crisis with hypotension, hyponatremia, hyperkalemia, and potentially life-threatening cardiovascular collapse. 2

• If discontinuation is necessary, taper over at least 1-3 days 2
• Patients should be under medical supervision during any dose reduction 2

Indication-Specific Dosing

Primary Adrenal Insufficiency (Addison's Disease):

• Standard dose: 0.1 mg daily 1
• Range: 0.05-0.2 mg daily 2, 6, 7

Salt-Losing Adrenogenital Syndrome:

• Recommended dose: 0.1-0.2 mg daily 1

Secondary Adrenal Insufficiency:

• Fludrocortisone is NOT required as aldosterone production remains intact 3
• Only glucocorticoid replacement is necessary 3

Patient Education Essentials

All patients with primary adrenal insufficiency requiring fludrocortisone must receive education on stress dosing, wear a medical alert bracelet, and have access to injectable hydrocortisone for emergencies. 3, 4

• Patients need instruction on when to increase glucocorticoid doses during acute illness 4
• Prescribe injectable hydrocortisone 100 mg for emergency use 4
• Endocrine consultation is recommended prior to surgery for stress-dose planning 3