Pharmacology
The physiologic action of fludrocortisone is similar to that of hydrocortisone. However, the effects of fludrocortisone, particularly on electrolyte balance, but also on carbohydrate metabolism, are considerably heightened and prolonged. In small oral doses, fludrocortisone 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 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.
Indications
Partial replacement therapy for primary and secondary adrenocortical insufficiency in Addison's disease and for the treatment of salt losing adrenogenital syndrome.
Precautions
See Pregnancy.
Adverse reactions to corticosteroids may be produced by too rapid withdrawal or by continued use of large doses.
To avoid drug induced adrenal insufficiency, supportive dosage may be required in times of stress (such as trauma, surgery, or severe illness) both during treatment with fludrocortisone and for a year afterwards.
There is an enhanced corticosteroid effect in patients with hypothyroidism and in those with cirrhosis.
Corticosteroids should be used cautiously in patients with ocular herpes simplex because of possible corneal perforation.
The lowest possible dose of corticosteroid should be used to control the condition being treated. A gradual reduction in dosage should be made when possible.
Psychic derangements may appear when corticosteroids are used. These may range from euphoria, insomnia, mood swings, personality changes, and severe depression, to frank psychotic manifestations. Existing emotional instability or psychotic tendencies may also be aggravated by corticosteroids.
ASA should be used cautiously in conjunction with corticosteroids in patients with hypoprothrombinemia.
Corticosteroids should be used with caution in patients with nonspecific ulcerative colitis if there is a probability of impending perforation, abscess, or other pyogenic infection.
Corticosteroids should also be used cautiously in patients with diverticulitis, fresh intestinal anastomoses, active or latent peptic ulcer, renal insufficiency, hypertension, osteoporosis, acute glomerulonephritis, vaccinia, varicella, exanthema, Cushing's syndrome, antibiotic resistant infections, diabetes mellitus, congestive heart failure, chronic nephritis, thromboembolitic tendencies, thrombophlebitis, convulsive disorders, metastatic carcinoma, and myasthenia gravis.
Growth and development of infants and children on prolonged corticosteroid therapy should be carefully observed.
Since adequate human reproduction studies have not been done with corticosteroids, the use of these drugs in pregnancy, nursing mothers, or women of childbearing potential requires that the possible benefits of the drug be weighed against the potential hazards to the mother, embryo, fetus or nursing infant. Infants born of mothers who have received substantial doses of corticosteroids during pregnancy should be carefully observed for signs of hypoadrenalism.
Supplied
Each white, scored tablet, imprinted with “RPC” and “059” contains: fludrocortisone acetate 0.1 mg. Bottles of 100. Store between 2 and 8°C.
Contraindications
Corticosteroids are contraindicated in patients with systemic fungal infections.
Warnings
No data supplied by the manufacturer.
Adverse Effects
peptic ulcer with possible perforation and hemorrhage, pancreatitis, abdominal distention, and ulcerative esophagitis.
sodium retention, fluid retention, congestive heart failure in susceptible patients, potassium loss, hypokalemic alkalosis, and hypertension.
muscle weakness, steroid myopathy, loss of muscle mass, osteoporosis, vertebral compression fractures, aseptic necrosis of femoral and humeral heads, pathologic fracture of long bones, and spontaneous fractures.
menstrual irregularities; development of the Cushingoid state; suppression of growth in children; secondary adrenocortical and pituitary unresponsiveness, particularly in times of stress (e.g. trauma, surgery, or illness); decreased carbohydrate tolerance; manifestations of latent diabetes mellitus; and increased requirements for insulin or oral hypoglycemic agents in diabetics.
Other adverse reactions that may occur following the administration of a corticosteroid are necrotizing angiitis, thrombophlebitis, aggravation or masking of infections, insomnia, syncopal episodes, and anaphylactoid reactions.
impaired wound healing, thin fragile skin, bruising, petechiae and ecchymoses, facial erythema, increased sweating, subcutaneous fat atrophy, purpura, striae, hyperpigmentation of the skin and nails, hirsutism, and acneiform eruptions; reactions to skin tests may be suppressed.
convulsions, increased intracranial pressure with papilledema (pseudotumor cerebri) usually after treatment, vertigo, headache, and severe mental disturbances.
hyperglycemia, glycosuria, and negative nitrogen balance due to protein catabolism.
posterior subcapsular cataracts, increased intraocular pressure, glaucoma, and exophthalmos.
Overdose
For management of a suspected drug overdose, CPhA recommends that you contact your regional Poison Control Centre. See the eCPS Directories section for a list of Poison Control Centres.
No data supplied by the manufacturer.
Dosage
Addison's disease: Usual dose is 0.1 mg daily, although dosage ranging from 0.1 mg 3 times a week to 0.2 mg daily has been employed. In the event transient hypertension develops as a consequence of therapy, the dose should be reduced to 0.05 mg daily. Fludrocortisone is preferably administered in conjunction with cortisone (10 to 37.5 mg daily in divided doses) or hydrocortisone (10 to 20 mg daily in divided doses).
Salt losing adrenogenital syndrome: 0.1 to 0.2 mg daily.
