FLORINEF
Clinical safety rating: caution
Comprehensive clinical and safety monograph for FLORINEF (FLORINEF).
Fludrocortisone is a synthetic corticosteroid with predominantly mineralocorticoid activity, promoting sodium retention and potassium excretion in the distal renal tubules, thereby increasing extracellular fluid volume and blood pressure.
| Metabolism | Primarily hepatic via CYP3A4-mediated metabolism; also metabolized by 11β-hydroxysteroid dehydrogenase to inactive metabolites. |
| Excretion | Renal: ~80% as metabolites, ~20% unchanged; minimal biliary/fecal elimination. |
| Half-life | Terminal elimination half-life: 3.5 hours; clinical effect half-life due to mineralocorticoid activity is longer (~12-24 hours), allowing once-daily dosing. |
| Protein binding | ~90% bound to corticosteroid-binding globulin (CBG) and albumin. |
| Volume of Distribution | Vd: ~0.3 L/kg; distributes mainly into extracellular fluid and binds to renal mineralocorticoid receptors. |
| Bioavailability | Oral: ~100% (well absorbed); no significant first-pass metabolism. |
| Onset of Action | Oral: 1-2 hours for sodium retention effect; peak effect at 12-24 hours. |
| Duration of Action | Duration of mineralocorticoid effect: 24 hours or longer; clinical duration for blood pressure and electrolyte effects persists for 24-48 hours after single dose. |
| Molecular Weight | 422.94 |
0.1 mg orally once daily, with range 0.1-0.2 mg/day. Dose may be divided twice daily if needed.
| Dosage form | TABLET |
| Renal impairment | No specific dose adjustment recommended based on GFR; use with caution in severe renal impairment due to sodium retention. |
| Liver impairment | No specific adjustment for Child-Pugh; monitor for fluid overload in severe hepatic impairment. |
| Pediatric use | 0.05-0.1 mg orally once daily; titrate based on response. |
| Geriatric use | Initiate at lower dose (0.05 mg daily) and titrate slowly; monitor for hypertension, hypokalemia, and fluid overload. |
| 1st trimester | Fluorocortisone, a mineralocorticoid, may be used if clearly needed. Animal studies have shown adverse effects, but human data are limited. Use only if potential benefit justifies risk. |
| 2nd trimester | Use with caution; may cause fetal electrolyte disturbances, growth restriction, or adrenal suppression. Monitor maternal and fetal status. |
| 3rd trimester | Use with caution; may cause fetal electrolyte disturbances, growth restriction, or adrenal suppression. Monitor maternal and fetal status. Prolonged use may lead to neonatal adrenal insufficiency. |
Clinical note
Comprehensive clinical and safety monograph for FLORINEF (FLORINEF).
| Placental transfer | Fluorocortisone crosses the placenta. The degree of transfer is likely similar to other corticosteroids, with some metabolism by placental 11β-HSD2, but significant fetal exposure can occur. |
| Breastfeeding | Fluorocortisone is excreted into breast milk in small amounts, but it is unlikely to cause adverse effects in the infant at therapeutic maternal doses. Caution is advised in high-dose or prolonged therapy due to potential for growth suppression or adrenal suppression. |
■ FDA Black Box Warning
None
| Serious Effects |
Systemic fungal infectionsHypersensitivity to fluorocortisone or any component of the formulation
| Precautions | May cause sodium retention and edema, especially in patients with cardiac disease, Monitor for hypokalemia and hyperglycemia, Increased risk of infections due to immunosuppression, May mask symptoms of infection, Do not use in patients with systemic fungal infections, Avoid abrupt discontinuation after prolonged therapy due to risk of adrenal insufficiency |
| Food/Dietary | Avoid excessive licorice (glycyrrhizin) which can enhance mineralocorticoid effects and worsen hypokalemia. Maintain a low-sodium diet to reduce fluid retention and hypertension. Increase potassium-rich foods if not contraindicated. |
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| Lactation Rating | L2 (Possibly Compatible) |
| Teratogenic Risk | Fludrocortisone (Florinef) is a corticosteroid with mineralocorticoid activity. In animal studies, corticosteroids have been associated with cleft palate and other malformations. Human data are limited. First trimester exposure may slightly increase risk of oral clefts. Second and third trimester use may suppress fetal adrenal function, leading to neonatal adrenal insufficiency. Overall risk is low with short-term use, but chronic high doses should be avoided. |
| Fetal Monitoring | Monitor maternal blood pressure, serum electrolytes (especially potassium), and signs of fluid overload. Monitor fetal growth and amniotic fluid volume if used long-term. Assess for neonatal adrenal insufficiency (e.g., hypoglycemia, hypotension) after delivery. |
| Fertility Effects | High doses of corticosteroids may impair fertility by disrupting hypothalamic-pituitary-adrenal axis and affecting ovulation. Fludrocortisone at usual doses is unlikely to significantly impact fertility, but any underlying condition requiring treatment may itself affect fertility. |
| Clinical Pearls | Monitor for signs of edema, hypertension, and hypokalemia. Use lowest effective dose. Caution in patients with heart failure, hypertension, or renal impairment. Do not abruptly discontinue; taper slowly. May interfere with cortisol assays. |
| Patient Advice | Take exactly as prescribed; do not stop suddenly without doctor's advice. · Weigh yourself daily and report rapid weight gain or swelling. · Monitor blood pressure regularly. · Eat a low-salt diet to help control fluid retention. · Report signs of high potassium (muscle weakness, irregular heartbeat) or low potassium (cramps, fatigue). · Carry medical ID indicating you take fludrocortisone. · Avoid excessive licorice intake (can worsen potassium loss). · May cause increased thirst and urination. |