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

(for veterinary information only)

Brand Name: Entocort EC, Entocord

Available in 3 mg microsized capsules as well as some products for inhalation

Background

Corticosteroids are the steroid hormones produced by the adrenal gland cortex. Two types of corticosteroids are produced. There are mineralocorticoids to control electrolyte balance and glucocorticoids to control sugar/calorie-burning metabolism. Because glucocorticoids have anti-inflammatory properties in higher doses they are widely used against many inflammatory conditions. Synthetic glucocorticoids, such as prednisone, are readily available and inexpensive but unfortunately there are side effects to be concerned about with long-term use. There is always interest in alternatives to corticosteroids.

Some inflammatory conditions involve inflammation at the site of an interface with the environment. Such interfaces include skin, the GI tract, and the respiratory tract. How nice it would be to have a corticosteroid that could be applied to the site of the inflammation but not be absorbed into the body systemically!  This is the idea behind budesonide. In the treatment of inflammatory bowel disease, for example, the idea is that budesonide is taken orally and moves along the intestinal tract with the rest of the intestinal contents, bathing the inflamed intestinal lining with corticosteroid treatment (similar to topically rubbing a cortisone cream on irritated skin). The budesonide is absorbed from the intestine but removed virtually immediately by the liver by what is called the first-pass effect. The body essentially sees only minimal steroid activity (the small amount that escapes the liver's detoxification mechanisms).

The problem with this seemingly ideal treatment plan is that budesonide is a strong corticosteroid, about fifteen times stronger than prednisone. This means that even the minimal amount that does get absorbed can be significant and it appears that the more inflamed the bowel lining is, the more budesonide is absorbed into the body. Appropriate dosing is important with this medication and one should note that experience with this drug in small animals is still limited.

Inhalant formulations of budesonide have been developed to treat asthma in humans but most veterinary interest has been about intestinal applications.

How this Medication is Used

Budesonide is typically given once daily for the treatment of inflammatory bowel disease.

Side Effects

Corticosteroid side effects include excessive thirst, appetite and urination. Excessive effects include the signs of Cushing's disease: hair loss on the trunk, pot-bellied appearance, and thin skin in more advanced stages. For a more complete description see the section on long-term steroid side effects.

Interactions with other Drugs

Drugs that interfere with the liver's ability to remove budesonide will lead to increased corticosteroid activity in the body. Drugs that have this effect include erythromycin (an antibiotic); cimetidine (an antacid); ketoconazole, fluconazole, and itraconazole (anti-fungals); and diltiazem (a heart medication).

Concerns and Cautions

Budesonide should be stored at room temperature.

Small animals require small doses of budesonide. A compounding pharmacy is frequently necessary to prepare an appropriately-sized capsule.

Budesonide would seem to be ideal for a patient that is intolerant of corticosteroid side effects (such as a patient with diabetes mellitus, an active infection, or other condition) but one must be aware that budesonide is not fully without corticosteroid activity.

Budesonide should not be used during pregnancy.

Liver disease may increase the potential for corticosteroid side effects seen with budesonide.

For budesonide to work properly, the capsules should not be opened or crushed.

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

Date Published: 7/10/2005 7:23:00 PM
Date Reviewed/Revised: 03/11/2009