By Rania Gollakner, BS, DVM, MPH

What is dexamethasone?

Dexamethasone (brand names: Azium®, Dexasone®, Decadron®, Dexium®, Dexameth-a-Vet®, Dex-a-vet®, Maxidex®, Neofordex®, Hexadrol®) is a glucocorticoid steroid medication used to treat many inflammatory conditions, patients with adrenal gland disease, and patients with immune-mediated diseases. It can also be used to diagnose Cushing’s disease (see handout "Dexamethasone Suppression Tests" for information on this diagnostic use of dexamethasone).

Its use in cats, dogs, other small mammals, and large animals to treat inflammatory conditions and other conditions is ‘off label’ or ‘extra label’. Many drugs are commonly prescribed for off label use in veterinary medicine. In these instances, follow your veterinarian’s directions and cautions very carefully as their direction may be significantly different from those on the label.

How is dexamethasone given?

Dexamethasone is given by mouth in the form of a tablet or liquid. It can also be given as an injection into the vein or muscle while in the clinic. Dexamethasone can also come in the form of an aerosol for respiratory conditions and a topical eye medication.

When given by mouth, it may be given with or without food, but preferably is given with food. If vomiting or nausea occurs when dosed on an empty stomach, give future doses with food or a treat. Measure liquid formulations carefully. NEVER give this medication with NSAIDs, as this can increase the occurrence and severity of stomach or intestinal ulcers.

This medication will take effect quickly, in about 1 to 2 hours, and improvement in clinical signs should follow. Do not stop this medication abruptly if your pet has been taking it for more than 2 weeks.

What if I miss giving my pet the medication?

If you miss a dose, give it when you remember, but if it is close to the time for the next dose, skip the dose you missed and give it at the next scheduled time, and return to the regular dosing schedule. Never give your pet two doses at once or give extra doses.

Are there any potential side effects?

Side effects of dexamethasone most commonly include increased drinking, urination, and appetite when given at any dose. Other side effects that occur, usually with higher doses, include dull/dry haircoat, weight gain, pot-bellied appearance, muscle weakness, panting, vomiting, diarrhea, or elevated fat or liver enzymes on bloodwork analysis.

More serious side effects include stomach or intestinal ulcers and bleeding, leading to black, tarry stools, bloody vomit, black specks like coffee grounds in the vomit, frank blood in the stools, loss of appetite, and/or fever. Other serious side effects include secondary infections, inflammation of the pancreas, activation or worsening of diabetes mellitus, muscle wasting, and severe changes in behavior.

This medication can also interfere with certain lab tests, including ACTH stimulation tests, blood cholesterol, ALP, urine glucose (sugar) levels, potassium levels, thyroid hormones, skin tests, and white blood cell counts.   

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?

Dexamethasone should not be used in pets that are allergic to it, or in pets with systemic fungal infections, diabetes, or stomach or intestinal ulcers. It should not be used in rabbits or in pets undergoing or recovering from surgery.

Caution should be used when giving dogs dexamethasone as it can cause gastrointestinal complications and bleeding. It should be used cautiously in cats as it can cause diabetes mellitus. Dexamethasone should be used cautiously in pets with kidney disease, heart disease, bacterial or fungal infections, or in pets that are pregnant or lactating. Use cautiously in young animals as this medication can retard growth. Do not stop this medication abruptly after long-term use (greater than 2 weeks); taper slowly to avoid complications.

Are there any drug interactions I should be aware of?

The following medications should be used with caution when given with dexamethasone: amphotericin b, anticholinesterase agents, aspirin, barbiturates, bupropion, cyclophosphamide, cyclosporine, diazepam, potassium-depleting diuretics, doxorubicin, ephedrine, fentanyl, fluoroquinolones, indomethacin, insulin, -azole antifungals, macrolides, mitotane, NSAIDs, phenobarbital, phenytoin, praziquantel, quinidine, rifampin, vaccines, and vincristine.

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

Is there any monitoring that needs to be done with this medication?

Depending on the dosage, duration, and your pet’s health status, your pet’s weight, appetite, electrolytes, blood proteins, and blood sugar levels should be monitored while using dexamethasone. Your veterinarian may also monitor your pet to be sure that the medication is working.

Watch for signs of swelling, and in young animals, watch for proper growth and development.

How do I store dexamethasone?

Store at room temperature between 15°C and 30°C (59°F and 86°F) and away from moisture and light unless otherwise recommended.


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.

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