FLUDROCORTISONE ACETATE

(for veterinary information only)

BRAND NAME FLORINEF

AVAILABLE IN
0.1 mg
TABLETS

USES OF THIS MEDICATION

There is really only one use for this medication: the treatment of Hypoadrenocorticism (Addison's disease). In this disease, the adrenal gland is unable to produce hormones called "mineralocorticoids." In the normal animal, these hormones are responsible for the balance of sodium and potassium and without these hormones a life-threatening circulatory shock ultimately results. Fludrocortisone acetate is a mineralocorticoid which can be given as a tablet to animals (or people) with Addison's disease to prevent this circulatory crisis.

It should be noted that an Addisonian crisis is an emergency and that, while fludrocortisone acetate is appropriate for prevention, it does not work fast enough in a crisis. An animal known to have Addison's disease that is also showing weakness, vomiting, diarrhea or appetite loss should have his/her sodium/potassium balance checked and should be seen by a veterinarian.

Fludrocortisone dosing has a "trial and error" aspect and it can be difficult to get to the best dose for a given patient. The process of trying a dose and testing electrolytes (i.e. sodium and potassium) can become expensive especially in larger dogs. Many people prefer a monthly injection of desoxycorticosterone pivalate (more commonly known as "DOCP" or by the brand names "percorten^®" or "zycortal^®") - see the library page on Addison's disease for more details.

HOW THIS MEDICATION WORKS

Fludrocortisone acetate acts on the kidney so as to conserve sodium and excrete potassium. Naturally occuring mineralocorticoids would act similarly were they present in adequate quantities.

Fludrocortisone is typically given twice a day and may be given with or without food. If a dose is accidentally skipped, give the dose when it is remembered and return to the regular dosing schedule but do not double up on the next dose. If a stressful event is anticipated, an extra dose may be needed.

SIDE EFFECTS

Fludrocortisone acetate has "glucocorticoid" properties in addition to its mineralocorticoid properties. This means that it acts in a fashion similar to that of prednisone and similar side effects can be observed. More specifically, if the cortisone levels get too high:

• Excessive thirst and urine production
• Weight gain and excessive appetite
• Hair loss/Poor coat

Please review the prednisone section for more information on side effects.

An overdose of fludrocortisone acetate could lead to high blood pressure, excess sodium retention and associated edema, weakness due to low potassium levels. Monitoring with periodic blood levels of sodium and potassium is crucial especially when the patient is just beginning therapy. The dose of medication will be dependent on these blood levels. A typical monitoring schedule would be electrolytes every 1-2 weeks until values are stable followed by testing quarterly.

INTERACTIONS WITH OTHER DRUGS

Blood potassium levels may drop dangerously low if this medication is used concurrently with a diuretic (such as furosemide or a member of the thiazide class of diuretics) or with the anti-fungal agent Amphoterecin B.

Fludrocortisone may also make diabetic patients more resistant to their usual dose of insulin.

Prednisone is generally not required in conjunction with fludrocortisone except during times of stress. This is because fludrocortisone acetate has adequate glucocorticoid properties on its own under ordinary circumstances but not under stressful circumstances.

CONCERNS AND CAUTIONS

Currently, an injectable mineralocorticoid called "DOCP" which may be given approximately every 25 days. Many experts feel that control of Addison's disease is superior with DOCP injections, though a corticosteroid such as prednisone generally must be given concurrently.

Fludrocortisone acetate is also available through compounding pharmacies in custom-made doses which, for larger dogs, often prove more cost-effective than multiple 0.1 mg manufactured tablets.

Page last updated: 4/5/2023