What is fludrocortisone acetate?

Fludrocortisone acetate (brand names: Florinef®, Astonin®, Astonin H®, Florinefe®, Lonikan®) is a mineralocorticoid used to treat adrenal gland insufficiency or hypoadrenocorticism (Addison’s disease). It may also be used with other medications to treat hyperkalemia.

Its use in cats, dogs, and ferrets to treat Addison’s disease is off label (extra label. Many drugs are commonly prescribed for off-label use in veterinary medicine. “Off label” means the drug is being used in a way that has not been reviewed or approved by the U.S. Food and Drug Administration (FDA) or Health Canada. In these instances, follow your veterinarian’s directions and cautions carefully, as they may be significantly different from those on the label.

How is fludrocortisone acetate given?

• Fludrocortisone acetate is given by mouth in the form of a tablet.
• It may be given with or without food; however, if vomiting occurs when dosed on an empty stomach, give future doses with food.
• Most pets will need glucocorticoid supplementation in addition to this medication, especially during times of stress.
• Do not stop giving this medication abruptly, as serious side effects can occur.

This medication will take effect quickly, in about 1 to 2 hours, and improvement in clinical signs should follow.

What if I miss giving my pet the medication?

If you miss a dose, give it as soon as you remember, and then continue with the regular dosing schedule. However, if it is almost time for the next dose, skip the missed dose and resume the regular dosing schedule. Do not give the pet two doses at once.

Are there any potential side effects?

Fludrocortisone acetate may cause the following side effects:

• Vomiting (uncommon)

Serious adverse reactions may occur with chronically high doses. If any of the following signs develop, stop giving fludrocortisone acetate and contact your veterinarian immediately:

• Increased thirst and urination
• Body swelling
• Weight gain
• Pot-belly appearance

Serious adverse reactions may occur with a dose that is too low. If any of the following signs develop, stop giving fludrocortisone acetate and contact your veterinarian immediately:

• Weakness
• Tiredness
• Shaking collapse
• Lack of appetite
• Vomiting
• Diarrhea
• Weight loss
• Low heart rate

This moderate-acting medication should stop working in a few days, although effects can be longer in pets with liver or kidney disease.

Are there any risk factors for this medication?

DO NOT USE fludrocortisone acetate in pets that:

• Are allergic to it

USE WITH CAUTION in pets that:

• Are lactating (if use in lactating animals is required, use a milk replacer)
• Are pregnant (limited information on safety)
• Have heart failure, kidney disease, or swelling

Are there any drug interactions I should be aware of?

Several medications should be used with caution when given with fludrocortisone acetate, including:

• Aspirin
• Bupropion
• Insulin
• Phenobarbital
• Potassium-depleting diuretics
• Vaccines

Be sure to tell your veterinarian about any medications (including vitamins, supplements, or herbal therapies) that your pet is taking before starting any new treatment.

Is any monitoring needed with this medication?

• Your veterinarian will monitor your pet’s electrolytes and kidney values regularly: every 1-2 weeks initially, and then every 3-6 months once stabilized.
• Your veterinarian will let you know when and how they want to reassess your pet to ensure the medication is working and not causing side effects.
• At home, monitor your pet for changes in weight, signs of edema (swelling), and any other side effects such as those noted above. If any occur, stop using the medication and contact your veterinarian.

How do I store fludrocortisone acetate?

• Store the tablets at room temperature between 59°F and 86°F (15°C and 30°C ),
• Protect from moisture and excessive heat.

What should I do in case of emergency?

If you suspect an overdose or an adverse reaction to the medication, call your veterinary office immediately. If they are not available, follow their directions in contacting an emergency facility. Be prepared to provide information about the product and your pet's weight and symptoms.