FLUDROCORTISONE ACETATE
Chemistry - A synthetic glucocorticoid with significant mineralocorticoid activity, fludrocortisoneacetate occurs as hygroscopic, fine, white to pale yellow powder or crystals. It is odorless orpractically odorless and has a melting point of approximately 225°C. Fludrocortisone is insolublein water and slightly soluble in alcohol.
Fludrocortisone acetate may also be known as fluohydrisone acetate, fluohydrocortisone acetate, 9alpha-fluorohydrocortisone acetate, or by the trade name Florinef® Acetate (SquibbMark).
The site of action of mineralocorticoids is at the renal distal tubule where it increases the absorption of sodium. Mineralocorticoids also enhance potassium and hydrogen ion excretion.
Uses, Indications - Fludrocortisone is used in small animal medicine for the treatment of adrenocortical insufficiency (Addison's disease). It has also been suggested to be used as adjunctivetherapy in hyperkalemia.
Additionally in humans, fludrocortisone has been used in salt-losing congenital adrenogenitalsyndrome and in patients with severe postural hypotension.
Contraindications/Precautions - Fludrocortisone is contraindicated in patients known to be hypersensitive to it.
Fludrocortisone may be excreted in clinically significant quantities in milk. Puppies or kittens ofmothers receiving fludrocortisone should receive milk replacer after colostrum is consumed.
Some dogs or cats may require additional supplementation with a glucocorticoid agent on anongoing basis. All animals with hypoadrenocorticism should receive additional glucocorticoids (2-10 times basal) during periods of stress or acute illness.
Overdosage - Overdosage may cause hypertension, edema and hypokalemia. Electrolytes shouldbe aggressively monitored and potassium may need to be supplemented. Patients should have thedrug discontinued until symptoms and signs associated with overdosage have resolved and thenrestart drug at a lower dosage.
As diuretics can cause a loss of sodium, they may counteract the effects fludrocortisone.
Potentially, fludrocortisone could increase the insulin requirements of diabetic patients or reduce salicylate blood levels. The clinical significance of these potential interactions with fludrocortisone have not been defined.
Fludrocortisone acetate may also be known as fluohydrisone acetate, fluohydrocortisone acetate, 9alpha-fluorohydrocortisone acetate, or by the trade name Florinef® Acetate (SquibbMark).
Storage, Stability, Compatibility
Fludrocortisone acetate tablets should be stored at room temperature (15-30°C) in well-closed containers; avoid excessive heat. The drug is relatively stable in light and air.Pharmacology - FLUDROCORTISONE ACETATE
Fludrocortisone acetate is a potent corticosteroid that possesses both glucocorticoid and mineralocorticoid activity. It is approximately 10-15 times as potent a glucocorticoid agent as hydrocortisone, but is a much more potent mineralocorticoid (125 times that of hydrocortisone). It is only used clinically for its mineralocorticoid effects.The site of action of mineralocorticoids is at the renal distal tubule where it increases the absorption of sodium. Mineralocorticoids also enhance potassium and hydrogen ion excretion.
Uses, Indications - Fludrocortisone is used in small animal medicine for the treatment of adrenocortical insufficiency (Addison's disease). It has also been suggested to be used as adjunctivetherapy in hyperkalemia.
Additionally in humans, fludrocortisone has been used in salt-losing congenital adrenogenitalsyndrome and in patients with severe postural hypotension.
Pharmacokinetics - FLUDROCORTISONE ACETATE
Fludrocortisone is well absorbed from the GI with peak levels occurring inapproximately 1.7 hours in humans. Also in humans, plasma half-life is about 3.5 hours, but biologic activity persists for 18-36 hours.Contraindications/Precautions - Fludrocortisone is contraindicated in patients known to be hypersensitive to it.
Fludrocortisone may be excreted in clinically significant quantities in milk. Puppies or kittens ofmothers receiving fludrocortisone should receive milk replacer after colostrum is consumed.
Adverse Effects, Warnings
Adverse effects of fludrocortisone are generally a result of excessivedosage (see Overdosage below) or if withdrawal is too rapid. Since fludrocortisone also possessesglucocorticoid activity, it theoretically could cause the adverse effects associated with thosecompounds. (See the section on the glucocorticoids following this monograph for more information.)Some dogs or cats may require additional supplementation with a glucocorticoid agent on anongoing basis. All animals with hypoadrenocorticism should receive additional glucocorticoids (2-10 times basal) during periods of stress or acute illness.
Overdosage - Overdosage may cause hypertension, edema and hypokalemia. Electrolytes shouldbe aggressively monitored and potassium may need to be supplemented. Patients should have thedrug discontinued until symptoms and signs associated with overdosage have resolved and thenrestart drug at a lower dosage.
Drug Interactions
Patients may develop hypokalemia if fludrocortisone is administered concomitantly with amphotericin B or potassium-depleting diuretics (e.g., thiazides, furosemide).As diuretics can cause a loss of sodium, they may counteract the effects fludrocortisone.
Potentially, fludrocortisone could increase the insulin requirements of diabetic patients or reduce salicylate blood levels. The clinical significance of these potential interactions with fludrocortisone have not been defined.