Fludrocortisone

# Fludrocortisone ## Overview - **Classification**: Mineralocorticoid (Corticosteroid) - **Mechanism**: Increases reabsorption of sodium and water in renal distal tubules and collecting ducts, while promoting potassium and hydrogen excretion. This leads to increased blood volume and blood pressure. ## Primary Indications 1. **Adrenocortical Insufficiency**: Partial replacement therapy in Addison's disease or other conditions with mineralocorticoid deficiency. 2. **Orthostatic Hypotension (Neurogenic)**: Management of symptomatic low blood pressure upon standing. ## Adult Dosing ### Standard Dosing **Adrenocortical Insufficiency (Addison's Disease)** - **Dose**: **0.05 mg** to **0.2 mg** - **Frequency**: Once daily - **Route**: Oral - **Special Considerations**: Always used in conjunction with a glucocorticoid. **Orthostatic Hypotension (Neurogenic)** - **Dose**: Initially **0.1 mg** - **Frequency**: Once or twice daily - **Route**: Oral - **Maximum Dose**: Titrate up to **1 mg** daily if needed, but rarely exceeds **0.2 mg** daily due to side effects. ### Dose Adjustments - **Renal Impairment**: No specific dose adjustments provided; use with caution due to risk of fluid retention and electrolyte imbalance. Monitor electrolytes closely. - **Hepatic Impairment**: No specific dose adjustments provided; use with caution. Monitor for fluid retention and electrolyte imbalance. - **Elderly Patients**: Start with lower doses (e.g., **0.05 mg** daily) and titrate slowly due to increased sensitivity to fluid/electrolyte effects (edema, hypertension). ## Pediatric Dosing ### Neonates (0-28 days) - **Indication**: Adrenocortical Insufficiency, Congenital Adrenal Hyperplasia (Salt-wasting form) - **Dose**: **0.05 mg** to **0.1 mg** - **Frequency**: Once daily - **Maximum**: Individualized, generally should not exceed **0.2 mg/day**. - **Special Notes**: Always used with a glucocorticoid. Monitor electrolytes, blood pressure, growth. ### Infants (1-12 months) - **Indication**: Adrenocortical Insufficiency, Congenital Adrenal Hyperplasia (Salt-wasting form) - **Dose**: **0.05 mg** to **0.1 mg** - **Frequency**: Once daily - **Maximum**: Individualized, generally should not exceed **0.2 mg/day**. ### Children (1-12 years) - **Indication**: Adrenocortical Insufficiency, Congenital Adrenal Hyperplasia (Salt-wasting form) - **Dose**: **0.05 mg** to **0.2 mg** - **Frequency**: Once daily - **Maximum**: **0.2 mg** daily (typical for CAH), up to **1 mg** daily for severe orthostatic hypotension (rare). ### Adolescents (13-18 years) - **Dose**: Generally follows adult dosing guidelines based on indication. - **Maximum**: Same as adult maximums (e.g., **0.2 mg** for adrenal insufficiency, **1 mg** for orthostatic hypotension). ## Safety Information ### Contraindications - **Absolute**: Systemic fungal infections (unless anti-infective therapy is being used). - **Absolute**: Hypersensitivity to fludrocortisone or any component. ### Common Adverse Effects - **Very Common (>10%)**: Hypertension, peripheral edema, weight gain. - **Common (1-10%)**: Hypokalemia, sodium retention, cardiac enlargement, congestive heart failure. - **Serious but Rare**: Adrenal suppression (with abrupt withdrawal), hypokalemic alkalosis, severe hypertension, acute pancreatitis. ### Key Drug Interactions - **Diuretics (thiazide or loop)**: Increased risk of hypokalemia. Monitor potassium. - **Digoxin**: Hypokalemia increases risk of digoxin toxicity. Monitor potassium and digoxin levels. - **NSAIDs**: Increased risk of fluid retention and GI ulceration/bleeding. Use with caution. - **Live Vaccines**: Contraindicated during high-dose steroid therapy due to immunosuppression. - **Antidiabetic Agents**: May increase blood glucose, requiring insulin/oral hypoglycemic dose adjustment. ## Monitoring & Follow-up - **Before Treatment**: Baseline blood pressure, serum electrolytes (Na, K), weight. - **During Treatment**: Blood pressure, serum electrolytes (especially potassium and sodium), and weight should be monitored regularly (e.g., weekly initially, then monthly). - **Clinical Signs**: Monitor for signs of fluid retention (edema, weight gain), hypertension, hypokalemia (muscle weakness, cramps, irregular heartbeat), and signs of steroid excess (Cushingoid features). ## Clinical Pearls - 💡 **Tip 1**: Administer once daily in the morning to align with natural diurnal cortisol rhythm. - 💡 **Tip 2**: Always take with food to minimize gastrointestinal upset. - 💡 **Tip 3**: Patients with adrenal insufficiency will also require a glucocorticoid (e.g., hydrocortisone). Fludrocortisone alone is insufficient. - 💡 **Tip 4**: Educate patients to monitor their weight daily and report sudden weight gain or swelling. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.