Dosage of Florinef (Fludrocortisone)
The standard dosage of Florinef (fludrocortisone) for Addison's disease is 0.1 mg daily, with a dosage range of 0.1 mg three times weekly to 0.2 mg daily, depending on the patient's response and disease severity. 1
Dosage Guidelines for Different Conditions
Primary Adrenal Insufficiency (Addison's Disease)
- Initial dose: 0.1 mg once daily 1
- Dosage range: 0.1 mg three times weekly to 0.2 mg daily 1
- Should be administered in conjunction with glucocorticoid replacement (typically hydrocortisone 15-25 mg/day in divided doses) 2, 3
- If transient hypertension develops, reduce dose to 0.05 mg daily 1
Salt-Losing Adrenogenital Syndrome
- Recommended dosage: 0.1 mg to 0.2 mg daily 1
Special Populations
- Children and younger adults may require higher doses (up to 500 μg daily) 2
- Pregnant women in the last trimester may need higher doses (up to 500 μg daily) due to progesterone counteracting mineralocorticoid effects 2
Administration Guidelines
- Fludrocortisone tablets are usually taken in one dose upon awakening 2
- Available in 0.1 mg and 0.05 mg tablet formulations 2
- Although the product label recommends refrigeration, the actual decay rate is only 0.1% in the first 6 months at room temperature 2
Monitoring and Dose Adjustment
- Dose should be adjusted based on clinical response 1
- Monitor for signs of under-replacement: salt cravings, lightheadedness, orthostatic hypotension 2
- Monitor for signs of over-replacement: hypertension, peripheral edema 2
- Blood pressure measurements in both supine and standing positions are helpful for dose titration 2
- Plasma renin activity should be maintained in the upper normal range 3
- Serum potassium should be maintained in the normal range 3
Drug Interactions
Medications that may require fludrocortisone dose adjustments:
- Diuretics (avoid) 2
- Acetazolamide (avoid) 2
- Carbenoxolone and licorice (avoid - potentiate mineralocorticoid effect) 2
- NSAIDs (avoid) 2
- Drospirenone-containing contraceptives (may need more fludrocortisone) 2
- Grapefruit juice (potentiates mineralocorticoid effect) 2
Precautions and Pitfalls
- Under-replacement is common and sometimes compensated for by over-replacement of glucocorticoids, which may predispose patients to adrenal crises 2
- Essential hypertension in a patient with primary adrenal insufficiency should be treated by adding a vasodilator, not by stopping mineralocorticoid replacement (though dose reduction should be considered) 2
- Patients should eat sodium salt and salty foods without restriction and avoid potassium-containing salts 2
- Unrestricted sodium intake is an important component of replacement therapy to avoid salt craving 2