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. |
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 | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for FLORINEF (FLORINEF).
| Breastfeeding | Fludrocortisone is excreted into breast milk in small amounts. The milk-to-plasma ratio is unknown. At typical doses, the amount ingested by the infant is likely to be low and not expected to cause adverse effects. However, monitor infant for signs of adrenal suppression. Use with caution, especially with high maternal doses. |
| 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. |
■ FDA Black Box Warning
None
| Serious Effects |
["Systemic fungal infections","Hypersensitivity to fludrocortisone or any component of the formulation","Concurrent live or attenuated virus vaccines (relative)"]
| 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"] |
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| 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. |