What is the recommended dosing regimen for Floraster (fludrocortisone)?

Fludrocortisone Dosing in Primary Adrenal Insufficiency

Fludrocortisone should be taken as a single daily dose of 50-200 μg upon awakening in the morning, with most adults requiring this range, though children, younger adults, and pregnant women in the third trimester may need up to 500 μg daily. 1

Standard Dosing Regimen

• Take fludrocortisone as a single morning dose upon awakening 1
• The typical starting dose is 0.05-0.1 mg (50-100 μg) daily 1
• Most patients with primary adrenal insufficiency require 50-200 μg daily for adequate replacement 1, 2
• The medication should be kept refrigerated per formulation instructions (FlorinefTM), though actual decay is only 0.1% in the first 6 months at room temperature 1

Dose Titration Based on Clinical Parameters

Increase the dose when:

• Salt cravings persist despite unrestricted sodium intake 1, 2
• Orthostatic hypotension is present (measure blood pressure supine and standing) 1
• Serum sodium is low or potassium is high 2
• Lightheadedness occurs 1

Decrease the dose when:

• Hypertension develops (reduce dose but do not stop completely) 1, 2
• Peripheral edema appears 1, 2
• Signs of over-replacement occur 1

Special Population Dosing

• Children and younger adults: May require higher doses up to 500 μg daily 1, 2
• Pregnancy (third trimester): Progesterone has anti-mineralocorticoid effects, often requiring dose increases up to 500 μg daily 1, 2
• Monitor using salt cravings, blood pressure, and serum electrolytes during pregnancy, as plasma renin activity normally increases and is not a reliable parameter 1

Critical Monitoring Parameters

Evaluate the following to guide dose adjustments:

• Blood pressure: Measure both supine and standing positions 1, 2
• Clinical symptoms: Assess for salt cravings, lightheadedness, and peripheral edema 1, 2
• Serum electrolytes: Monitor sodium and potassium levels 2
• Weight and volume status: Check for fluid retention 2

Dietary Recommendations

• Encourage unrestricted sodium intake and salty foods to prevent salt craving, which is an important component of therapy 1, 2
• Avoid potassium-containing salt substitutes often marketed as "healthy" 1, 2
• Avoid liquorice and grapefruit juice as they potentiate mineralocorticoid effects and may lead to over-replacement 1, 2

Drug Interactions Requiring Dose Adjustment or Avoidance

Avoid these medications:

• Diuretics 1, 2
• Acetazolamide 1, 2
• Carbenoxolone and liquorice 1, 2
• NSAIDs 1, 2

May require increased fludrocortisone:

• Drospirenone-containing contraceptives 1, 2

Common Pitfalls and How to Avoid Them

Under-replacement is extremely common and often compensated for by over-replacement of glucocorticoids, predisposing patients to recurrent adrenal crises 1, 2. Research shows that patients on 0.05-0.1 mg daily with undetectable aldosterone levels are frequently undertreated, with most requiring 0.2 mg for adequate sodium balance 3.

Never completely stop fludrocortisone when hypertension develops—instead, reduce the dose and consider adding a vasodilator for essential hypertension 1, 2. Abrupt discontinuation can trigger adrenal crisis with hypotension, hyponatremia, hyperkalemia, and potentially life-threatening cardiovascular collapse 2.

Do not rely solely on plasma renin activity during pregnancy for dose adjustment, as it normally increases; instead use clinical symptoms, blood pressure, and electrolytes 1.

Monitoring Schedule

• Patients should be reviewed at least annually 2
• Assessment should include weight, blood pressure (supine and standing), and serum electrolytes 2
• Monitor for hypokalaemia, which can develop in 24% of patients at a mean of 8 months 4