Fludrocortisone

Fludrocortisone, sold under the brand name Florinef among others, is a corticosteroid used to treat congenital adrenal hyperplasia, postural hypotension, and adrenal insufficiency. In adrenal insufficiency, it is generally taken together with hydrocortisone. Fludrocortisone is taken by mouth and is most commonly used in its acetate form.

Common side effects of fludrocortisone include high blood pressure, swelling, heart failure, and low blood potassium. Other serious side effects can include low immune-system function, cataracts, muscle weakness, and mood changes. Whether use of fludrocortisone during pregnancy is safe for the fetus is unknown. Fludrocortisone is mostly a mineralocorticoid, but it also has glucocorticoid effects.

Fludrocortisone was patented in 1953. It is on the World Health Organization's List of Essential Medicines.

Fludrocortisone has been used in the treatment of cerebral salt-wasting syndrome. It is used primarily to replace the missing hormone aldosterone in various forms of adrenal insufficiency such as Addison's disease and the classic salt-wasting (21-hydroxylase deficiency) form of congenital adrenal hyperplasia. Due to its effects on increasing Na+ levels, and therefore blood volume, fludrocortisone is the first-line of treatment for orthostatic intolerance, and postural orthostatic tachycardia syndrome (POTS). It can be used to treat low blood pressure.

Fludrocortisone is also a confirmation test for diagnosing Conn's syndrome (aldosterone-producing adrenal adenoma), the fludrocortisone suppression test. Loading the patient with fludrocortisone would suppress serum aldosterone level in a normal patient, whereas the level would remain elevated in a Conn's patient. The fludrocortisone suppression test is an alternative to the NaCl challenge (which would use normal saline or salt tablets).^{[medical citation needed]}

Use of fludrocortisone can lead to one or more of the following side effects:

Fludrocortisone is a corticosteroid and acts as a powerful mineralocorticoid, along with some additional but comparatively very weak glucocorticoid activity. Relative to cortisol, it is said to have 10 times the glucocorticoid potency but 250 to 800 times the mineralocorticoid potency. Fludrocortisone acetate is a prodrug of fludrocortisone, which is the active form of the drug.

Plasma renin, sodium, and potassium are checked through blood tests to verify that the correct dosage is reached.^{[medical citation needed]}