FLUDROCORTISONE ACETATE- fludrocortisone acetate tablet
Barr Laboratories Inc.
Iss. 11/2010
Rx only
DESCRIPTION
Fludrocortisone acetate tablets USP contain fludrocortisone acetate, a synthetic adrenocortical steroid possessing very potent mineralocorticoid properties and high glucocorticoid activity; it is used only for its mineralocorticoid effects. The chemical name for fludrocortisone acetate is 9-fluoro-11� , 17, 21-trihydroxypregn-4-ene-3,20-dione 21-acetate. The structural formula is as follows:
Structural Formula
(click image for full-size original)
C23 H31 FO6 M.W. 422.49
Fludrocortisone acetate tablets USP are available for oral administration as scored tablets providing 0.1 mg fludrocortisone acetate, USP per tablet. In addition, each tablet contains the following inactive ingredients: anhydrous lactose, corn starch, dibasic calcium phosphate, D&C yellow no. 10 aluminum lake, magnesium stearate, sodium starch glycolate, and talc.
CLINICAL PHARMACOLOGY
Corticosteroids are thought to act, at least in part, by controlling the rate of synthesis of proteins. Although there are a number of instances in which the synthesis of specific proteins is known to be induced by corticosteroids, the links between the initial actions of the hormones and the final metabolic effects have not been completely elucidated.
The physiologic action of fludrocortisone acetate is similar to that of hydrocortisone. However, the effects of fludrocortisone acetate, particularly on electrolyte balance, but also on carbohydrate metabolism, are considerably heightened and prolonged. Mineralocorticoids act on the distal tubules of the kidney to enhance the reabsorption of sodium ions from the tubular fluid into the plasma; they increase the urinary excretion of both potassium and hydrogen ions. The consequence of these three primary effects together with similar actions on cation transport in other tissues appear to account for the entire spectrum of physiological activities that are characteristic of mineralocorticoids. In small oral doses, fludrocortisone acetate produces marked sodium retention and increased urinary potassium excretion. It also causes a rise in blood pressure, apparently because of these effects on electrolyte levels.
In larger doses, fludrocortisone acetate inhibits endogenous adrenal cortical secretion, thymic activity, and pituitary corticotropin excretion; promotes the deposition of liver glycogen; and, unless protein intake is adequate, induces negative nitrogen balance.
The approximate plasma half-life of fludrocortisone (fluorohydrocortisone) is 3.5 hours or more and the biological half-life is 18 to 36 hours.
INDICATIONS AND USAGE
Fludrocortisone acetate tablets are indicated as partial replacement therapy for primary and secondary adrenocortical insufficiency in Addison�s disease and for the treatment of salt-losing adrenogenital syndrome.
