Budesonide for Cats

Budesonide, a corticosteroid originally formulated to treat Chron's disease in humans, has found use in cats with inflammatory bowel disease (IBD).
Corticosteroids like prednisone are commonly prescribed to relieve feline IBD. Over time, however, the amounts of prednisone absorbed may suppress a cat's natural steroid production, resulting in Cushing's disease. Budesonide is less absorbable than other corticosteroids and avoids this problem.

How Budesonide Works

Inflammatory bowel disease occurs when a cat's immune system sends an excessive number of cells into the gastrointestinal tract lining, thickening it so that it neither absorbs nutrients nor moves food properly. Budesonide (brand name Entocord) is delivered in capsules resistant to digestive juices, reaching the GI tract intact where they dissolve, providing relief to the inflamed tissues.
The liver immediately filters budesonide, so very little of it remains to affect the endocrine system's natural corticosteroid production.

Budesonide Dosing

Budesonide is far stronger than prednisone and other commonly prescribed corticosteroids. Even the small amounts which escape liver filtration and get absorbed can affect a cat's endocrine system. Veterinarian Wendy C. Brooks notes that the amount of budesonide absorbed increases in proportion to the severity of bowel inflammation, so the sickest cats are likely to absorb the most.
According to the drug's maker AstraZeneca, healthy humans absorb only about 10 percent of their doses, while in people with Chron's disease the absorption rate is 20 percent. Properly dosing a cat with budesonide is critical. The Merck Veterinary Manual suggests a dose of 1 mg per day. The capsules must be swallowed whole to be effective.
Dr. Brooks suggests finding a compounding pharmacist to prepare doses specifically for individual cats (see Resources).

Side Effects

Like all corticosteroids, budesonide has potential side effects. Cats taking it may exhibit increased hunger, thirst and urination. Those absorbing it in high amounts may develop Cushing's disease. Symptoms are thin skin, hair loss and a pot belly.

Contraindications

Cats receiving drugs which compromise their livers' filtering abilities may end up absorbing larger amounts of budesonide. Some of these drugs include the antibiotic erythromycin, dilatiazem for the heart and the antifungals itraconazole, fluconazole and ketaconazole.
Pregnant cats and those with liver disease shouldn't get budesonide.

Storing Budesonide

Store budesonide in its tightly sealed original container, and make sure that the temperature where it is stored remains below 86 degrees F.

References

• Veterinary Partner
• AstraZeneca
• Merck Veterinary Manual

Resources

• Compounding Pharmacies