Brand Name: Azium, Voren

Available in 0.25 mg, 0.50 mg, 0.75 mg, 1 mg, 1.5 mg, 2 mg, 4 mg and 6 mg tablets; oral solution; several eye drop formulations

Uses of this Medication

Dexamethasone is a member of the glucocorticoid class of hormones. This means they are steroids, but unlike the anabolic steroids you may have heard that are used in sports medicine, these are catabolic steroids. Instead of building the body up, they are designed to break down stored resources (fats, sugars, and proteins) so that they may be used as fuels in times of stress. Cortisone would be an example of a related hormone with which most people are familiar, though cortisone (more correctly called cortisol) is a natural hormone produced by the body's adrenal glands, whereas dexamethasone is synthetic.

Glucocorticoids are not used for their influences on glucose and protein metabolism but are used because, in higher doses, they are broadly anti-inflammatory.

Their uses fit into several groups:

• Anti-inflammatory - especially for joint pain and itchy skin.
• Immune-suppression - treating conditions where the immune system is destructively hyperactive. Higher doses are required to actually suppress the immune system.
• Cancer chemotherapy - although usually prednisolone, another steroid, is favored for this use.
• Central nervous system disorders - usually after a disk episode to relieve swelling in the spinal cord.
• Dexamethasone also has some use in pregnancy termination in dogs.

Side Effects

Dexamethasone is commonly used for several weeks or even months at a time to get a chronic process under control. Once the condition is controlled, it is important that the dose be tapered to the lowest effective dosing frequency once the condition is controlled. The reason for this is that the body will perceive these hormones and not produce any of its own. In time, the adrenal glands will atrophy so that when the medication is discontinued, the patient will be unable to respond to any stressful situation.

A blood sugar crisis can result. Using the medication every other day allows the body's own adrenal glands to remain active.

• Do not abruptly discontinue this medication. If you wish to discontinue use, consult your veterinarian about tapering it down.
• If a dose is accidentally skipped, do not double the next dose; simply pick up where you left off with the next dose.

Any latent infections can be unmasked by dexamethasone use. (Feline upper respiratory infections are a classical example. When a cat recovers clinically, the infection simply goes dormant. Glucocorticoid use could bring the infection out again.)

Glucocorticoid hormone use can be irritating or even ulcerating to the stomach or intestine at higher doses.

Long-term steroid use strongly predisposes a patient to latent urinary tract infection. Such infections may not have apparent symptoms because the inflammation responsible for the symptoms is suppressed by the steroid.

Glucocorticoids are called diabetogenic hormones, which means that with long-term use or in predisposed patients, they can induce diabetes mellitus. They should not be used in patients who already have diabetes mellitus.

Panting is a common corticosteroid hormone side effect.

Appetite loss, vomiting, or diarrhea should be reported to your veterinarian.

Interactions with Other Drugs

Glucocorticoid hormones should not be used in combination with medications of the NSAID class (i.e. aspirin, carprofen, meloxicam, etc.) as the combination of these medications could lead to bleeding in the stomach or intestine. Ulceration could occur. Similarly, dexamethasone should not be used with other corticosteroids.

Macrolide antibiotics (such as clarithromycin or erythromycin) can increase dexamethasone blood levels. Using the antifungal ketoconazole can have a similar interaction.

Diuretics that work by reducing blood potassium levels can create significantly low blood potassium levels when combined with dexamethasone.

Concerns and Cautions

Dexamethasone is considered a long-acting steroid, meaning that a dose lasts about two or two-and-a-half days. For this reason, an every-other-day schedule is excessive; the goal is every third day or less.

The same salt retention that accounts for excessive thirst and urination may also be a problem for heart failure patients or other patients who require sodium restriction.

Dexamethasone use is likely to change liver enzyme blood testing and interfere with testing for thyroid diseases.

Dexamethasone is approximately 10 times stronger than prednisone/prednisolone.

Monitoring tests will likely be recommended if this medication is used long-term.

Read more about chronic steroid use.

Read more about steroid alternatives for relieving itchy skin.