THE PET PHARMACY By Wendy C. Brooks, DVM, DipABVP Educational Director, VeterinaryPartner.com

Brand Name: Azium or Voren

Available in 0.25 mg, 0.75 mg, 1 mg, 1.5 mg, 2 mg, 4 mg and 6 mg tablets   
      
Uses of this Medication

Dexamethasone is a member of the glucocorticoid class of hormones. This means they are steroids but unlike the anabolic steroids that we hear about 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 is an example of a related hormone with which most people are familiar.  Cortisone (more correctly called cortisol) is a natural hormone produced by the body's adrenal glands, whereas dexamethasone is synthetic.

In most cases, we do not use glucocorticoids for their influences on glucose and protein metabolism; we use them 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 - treatment of conditions where the immune system is destructively hyperactive. Higher doses are required to actually suppress the immune system.
  
  
• Cancer chemotherapy - especially in the treatment of lymphoma
  
  
• Central nervous system disorders - usually after trauma or after a disc episode to relieve swelling in the brain or spinal cord.
  
  
• Shock - steroids seem to help improve circulation though this use is somewhat controversial.
  
  
• Blood calcium reduction - in medical conditions where blood calcium is dangerously high treatment is needed to reduce levels to normal.
  
  
• 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 an every third day schedule. The reason for this is that body will perceive the presence of 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 circulatory crisis can result. By using the medication every other day, this allows the body's own adrenal glands to remain active.

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 to the stomach 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.

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.

Concerns and Cautions

Dexamethasone is considered to be 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 for dexamethasone; every third day or less is the goal for dexamethasone.

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.

It is our policy not to give dosing information over the Internet.

Date Published: 1/1/2001
Date Reviewed/Revised: 12/01/2009