(for veterinary information only)
0.25 mg, 0.75 mg, 1 mg
1.5 mg, 2 mg, 4 mg & 6 mg
Dexamethasone is a member of the glucocorticoid class of hormones. This means they are steroids but, unlike the anabolic steroids that we hear about regarding 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.
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 the dog.
Dexamethasone is commonly used for several weeks or even months at a time to get a chronic process under control. It is important that the dose be tapered to an every third day schedule once the condition is controlled. 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. An actual 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 would be 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.
Glucocorticoid hormones should not be used in combination with medications of the NSAID class (ie aspirin, carprofen, meloxicam etc.) as the combination of these medications could lead to bleeding in the stomach or intestine. Ulceration could occur.
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 will be excessive for dexamethasone; every third day (or less) is the goal for dexamethasone.
The same salt retention that accounts for the excessive thirst and urination may also be a problem for heart failure patients or other patients who require sodium restriction.
Diabetic patients should never take this medication
unless there is a life-threatening reason why they must.
Glucocorticoid hormones can cause abortion in pregnant patients.
This class of hormone should not be used in pregnancy.
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.
Click here for more information about Chronic Steroid Use.
Click here for information on Steroid Alternatives for Itchy Skin.
Page last updated: 2/4/10